Table Of Content- An ab initio, DFT and semiempirical SCF-MO package -
Version 2.8-20 September 2010
Design
andScientific
Directorship:
Frank Neese
Technical
Directorship:
Frank Wennmohs
Lehrstuhl
für
Theoretische
Chemie
Wegelerstr.
12D-‐53115
Bonn,
Germany
[email protected]‐bonn.de
With
contributions
from:
Ute Becker, Dmitry Ganyushin, Andreas Hansen, Dimitrios G. Liakos, Christian Kollmar,
Simone Kossmann, Taras Petrenko, Christoph Reimann, Christoph Riplinger,
Kantharuban Sivalingam, Edward Valeev, Boris Wezisla
Input
Description
TABLE
OF
CONTENTS
1
GENERAL INFORMATION........................................................................................11
1.1
PROGRAM COMPONENTS.............................................................................................11
1.2
UNITS AND CONVERSION FACTORS.............................................................................12
2
PUBLICATIONS RELATED TO ORCA....................................................................13
3
CALLING THE PROGRAM (SERIAL AND PARALLEL).....................................23
3.1
CALLING THE PROGRAM..............................................................................................23
3.2
HINTS ON THE USE OF PARALLEL ORCA.....................................................................26
4
GENERAL STRUCTURE OF THE INPUT FILE.....................................................29
4.1
INPUT BLOCKS............................................................................................................29
4.2
KEYWORD LINES........................................................................................................31
4.3
ORCA AND SYMMETRY.............................................................................................42
4.4
USE OF EFFECTIVE CORE POTENTIALS........................................................................43
4.5
JOBS WITH MULTIPLE STEPS......................................................................................50
5
INPUT OF COORDINATES........................................................................................51
6
RUNNING TYPICAL CALCULATIONS...................................................................54
6.1
SINGLE POINT ENERGIES AND GRADIENTS....................................................................54
6.1.1
Hartree-Fock......................................................................................................54
6.1.1.1
Standard single points.........................................................................................................................54
6.1.1.2
Basis Set Options................................................................................................................................55
6.1.1.3
SCF and Symmetry.............................................................................................................................56
6.1.2
MP2....................................................................................................................59
6.1.2.1
MP2 and RI-MP2 Energies.................................................................................................................59
6.1.2.2
Orbital Optimized MP2 methods........................................................................................................60
6.1.2.3
MP2 and RI-MP2 Gradients...............................................................................................................61
6.1.2.4
Frozen core options............................................................................................................................63
6.1.2.5
MP2 Densities and Natural Orbitals...................................................................................................63
6.1.3
Coupled Cluster and Coupled Pair Methods.....................................................64
6.1.3.1
Basics..................................................................................................................................................64
6.1.3.2
Static versus Dynamic Correlation.....................................................................................................68
6.1.3.3
Basis Sets for Correlated Calculations. The case of ANOs................................................................72
6.1.3.4
Automatic extrapolation to the basis set limit....................................................................................75
Orca Version 2 - Input Description 3
6.1.3.5
Local Coupled Pair and Coupled Cluster Calculations......................................................................79
6.1.4
Density Functional.............................................................................................82
6.1.4.1
Standard Density Functional Calculations.........................................................................................82
6.1.4.2
DFT Calculations with RI...................................................................................................................83
6.1.4.3
Hartree-Fock and Hybrid DFT Calculations with RIJCOSX.............................................................85
6.1.4.4
Hartree-Fock and Hybrid DFT Calculations with RI-JK...................................................................86
6.1.4.5
DFT Calculations with Second Order Perturbative Correction (double hybrid functionals).............87
6.1.4.6
DFT Calculations with Empirical Van der Waals Correction............................................................88
6.1.5
Quadratic Convergence......................................................................................89
6.1.6
Counterpoise Correction....................................................................................91
6.1.7
Complete Active Space Self-Consistent Field.....................................................93
6.1.7.1
Introduction........................................................................................................................................93
6.1.7.2
A simple example...............................................................................................................................94
6.1.7.3
Starting Orbitals..................................................................................................................................96
6.1.7.4
CASSCF and Symmetry...................................................................................................................101
6.1.7.5
RI and RIJCOSX approximations for CASSCF...............................................................................105
6.1.7.6
Breaking Chemical Bonds................................................................................................................106
6.1.7.7
Excited States...................................................................................................................................111
6.1.7.8
CASSCF Natural Orbitals as input for Coupled Cluster Calculations.............................................113
6.1.8
N-Electron Valence State Perturbation Theory (NEVPT2)..............................118
6.1.8.1
Introduction......................................................................................................................................118
6.1.8.2
A simple example.............................................................................................................................119
6.1.8.3
RI Approximation.............................................................................................................................120
6.1.8.4
Parametric surface scans...................................................................................................................120
6.1.8.5
Approximations for large active CASSCF space.............................................................................121
6.1.8.6
State-averaged NEVPT2...................................................................................................................122
6.1.9
Scalar Relativistic SCF.....................................................................................123
6.1.9.1
Douglas-Kroll-Hess..........................................................................................................................123
6.1.9.2
ZORA and IORA..............................................................................................................................124
6.1.10
How to do efficient calculations with atomic natural orbitals?.......................125
6.2
GEOMETRY OPTIMIZATIONS, SURFACE SCANS, TRANSITION STATES, MECPS..........127
6.2.1
Geometry Optimizations..................................................................................127
6.2.2
Numerical Gradients........................................................................................128
6.2.3
Some Notes and Tricks.....................................................................................128
6.2.4
Initial Hessian for minimization.......................................................................129
6.2.5
Coordinate systems for Optimizations..............................................................130
6.2.6
Constrained Optimizations...............................................................................131
6.2.7
Constrained Optimizations for Molecular Clusters (Fragment Optimization).133
Orca Version 2 - Input Description 4
6.2.8
Relaxed Surface Scans......................................................................................135
6.2.9
Multiple XYZ file scans.....................................................................................138
6.2.10
Transition States...............................................................................................138
6.2.10.1
Introduction to Transition State Searches....................................................................................138
6.2.10.2
Hessians for Transition State Calculations..................................................................................141
6.2.10.3
Special Coordinates for Transition State Optimizations..............................................................143
6.2.11
MECP optimization..........................................................................................143
6.2.12
Using the Gaussian optimizer..........................................................................145
6.2.13
ORCA as external optimizer............................................................................146
6.3
VIBRATIONAL FREQUENCIES.....................................................................................146
6.4
REACTION ENERGIES FROM COMPOUND JOBS...........................................................148
6.5
EXCITED STATES WITH CIS, CIS(D) AND TD-DFT..................................................150
6.5.1
General Use......................................................................................................151
6.5.2
Use of TD-DFT for the calculation of X-ray absorption spectra.....................151
6.5.3
Excited state Geometry optimization................................................................155
6.5.4
Doubles correction...........................................................................................155
6.6
MULTIREFERENCE CONFIGURATION INTERACTION AND PERTURBATION THEORY.....156
6.6.1
Introductory Remarks.......................................................................................156
6.6.1.1
Introduction......................................................................................................................................156
6.6.1.2
RI-approximation..............................................................................................................................156
6.6.1.3
Individual Selection..........................................................................................................................157
6.6.1.4
Single excitations..............................................................................................................................157
6.6.1.5
Reference Spaces..............................................................................................................................157
6.6.1.6
Size Consistency...............................................................................................................................158
6.6.1.7
Performance......................................................................................................................................158
6.6.1.8
Symmetry..........................................................................................................................................159
6.6.2
A Tutorial Type Example of a MR Calculation................................................160
6.6.3
Excitation Energies between different multiplicities........................................175
6.6.4
Correlation Energies........................................................................................176
6.6.5
Thresholds........................................................................................................177
6.6.5.1
Reference Values for Total Energies................................................................................................177
6.6.5.2
Convergence of Single Reference Approaches with Respect to T ................................................178
sel
6.6.5.3
Convergence of Multireference Approaches with Respect to T ...................................................178
pre
6.6.6
Energy Differences – Bond Breaking...............................................................180
6.6.7
Energy Differences – Spin Flipping.................................................................182
6.6.8
Potential Energy Surfaces................................................................................184
Orca Version 2 - Input Description 5
6.6.9
Multireference Systems – Ozone.......................................................................187
6.6.10
Size Consistency...............................................................................................189
6.6.11
Efficient MR-MP2 calculations for larger molecules.......................................190
6.7
SOLVATION...............................................................................................................191
6.8
CALCULATION OF PROPERTIES..................................................................................193
6.8.1
Population Analysis and Related Things..........................................................193
6.8.2
Absorption and Fluorescence Bandshapes.......................................................197
6.8.3
IR/Raman spectra, Vibrational Modes and Isotope Shifts...............................202
6.8.3.1
IR Spectra.........................................................................................................................................202
6.8.3.2
Raman Spectra..................................................................................................................................204
6.8.3.3
Resonance Raman Spectra................................................................................................................206
6.8.3.4
NRVS Spectra...................................................................................................................................206
6.8.3.5
Animation of Vibrational Modes......................................................................................................207
6.8.3.6
Isotope Shifts....................................................................................................................................208
6.8.4
Thermochemistry..............................................................................................210
6.8.5
Electric Properties............................................................................................213
6.8.6
NMR Chemical Shifts.......................................................................................214
6.8.7
Hyperfine and Quadrupole Couplings.............................................................216
6.8.8
The EPR g-Tensor and the Zero-Field Splitting Tensor..................................219
6.8.9
‘Broken-Symmetry’ Wavefunctions and Exchange Couplings.........................221
7
DETAILED DOCUMENTATION.............................................................................224
7.1
MORE ON COORDINATE INPUT..................................................................................224
7.1.1
Fragment Specification....................................................................................224
7.1.2
Defining Geometry Parameters and Scanning Potential Energy Surfaces......225
7.1.3
Inclusion of Point Charges...............................................................................227
7.2
CHOICE OF COMPUTATIONAL MODEL.......................................................................228
7.2.1
Features Common to All Calculations.............................................................228
7.2.2
Density functional calculations........................................................................230
7.2.2.1
Choice of Functional........................................................................................................................230
7.2.2.2
Choice of Integration Grid................................................................................................................235
7.2.2.3
Using the RI-J approximation to the Coulomb part.........................................................................241
7.2.2.4
The Split-RI-J Coulomb Approximation..........................................................................................243
7.2.2.5
Using the RI Approximation for Hartree-Fock and Hybrid DFT (RIJONX)...................................244
7.2.2.6
Using the RI Approximation for Hartree-Fock and Hybrid DFT (RIJCOSX).................................245
7.2.2.7
Improved Analytical Evaluation of the Coulomb term: Split-J........................................................247
7.2.2.8
The Standard Basis Sets and Computational Levels........................................................................247
Orca Version 2 - Input Description 6
7.2.3
Second Order Møller-Plesset Perturbation Theory.........................................248
7.2.4
Semiempirical Methods....................................................................................251
7.3
CHOICE OF BASIS SET...............................................................................................255
7.3.1
Built in Basis Sets.............................................................................................255
7.3.2
Assigning or Adding Basis Functions to an Element.......................................260
7.3.3
Assigning or Adding Basis Functions to Individual Atoms..............................261
7.3.4
Reading orbital and auxiliary basis sets from a file.........................................262
7.4
CHOICE OF INITIAL GUESS AND RESTART OF SCF CALCULATIONS...........................263
7.4.1
AutoStart feature..............................................................................................263
7.4.2
One Electron Matrix Guess..............................................................................264
7.4.3
Basis Set Projection..........................................................................................264
7.4.4
PModel Guess...................................................................................................264
7.4.5
Hueckel and PAtom Guesses............................................................................265
7.4.6
Restarting SCF Calculations............................................................................265
7.4.7
Changing the Order of Initial Guess MOs and Breaking the Initial Guess Symmetry
266
7.5
SCF CONVERGENCE.................................................................................................267
7.5.1
Convergence Tolerances..................................................................................267
7.5.2
Dynamic and Static Damping...........................................................................269
7.5.3
Level Shifting....................................................................................................270
7.5.4
Direct Inversion in Iterative Subspace (DIIS)..................................................270
7.5.5
An alternative DIIS algorithm: KDIIS..............................................................271
7.5.6
Approximate Second Order SCF (SOSCF)......................................................271
7.5.7
Full Second Order SCF (NR)...........................................................................272
7.5.8
Fractional Occupation Numbers......................................................................275
7.6
CHOICE OF WAVEFUNCTION AND INTEGRAL HANDLING...........................................276
7.6.1
Choice of Wavefunction Type...........................................................................276
7.6.2
UHF Natural Orbitals......................................................................................279
7.6.3
Integral Handling (Conventional, Direct, SemiDirect)....................................279
7.7
THE SECOND ORDER MANY BODY PERTURBATION THEORY MODULE (MP2)..........283
7.7.1
Standard MP2...................................................................................................283
7.7.2
RI-MP2.............................................................................................................284
7.7.3
Orbital Optimized MP2....................................................................................292
Orca Version 2 - Input Description 7
7.7.4
RICOSX-RI-MP2 Gradients.............................................................................296
7.8
THE SINGLE REFERENCE CORRELATION MODULE....................................................297
7.8.1
Theory...............................................................................................................297
7.8.2
Closed shell equations......................................................................................301
7.8.3
Open shell equations (spin-unrestricted formalism)........................................305
7.8.4
Use of the MDCI Module.................................................................................305
7.9
THE COMPLETE ACTIVE SPACE SELF-CONSISTENT FIELD (CASSCF) MODULE........307
7.9.1
General Description.........................................................................................307
7.9.2
CASSCF Properties.........................................................................................318
7.10
N-ELECTRON VALENCE STATE PERTURBATION THEORY......................................319
7.11
RELATIVISTIC OPTIONS.........................................................................................320
7.12
GEOMETRY OPTIMIZATION....................................................................................324
7.13
EXCITED STATES VIA CIS AND TD-DFT................................................................342
7.13.1
General Features..............................................................................................343
7.13.2
Semiempirical Methods....................................................................................344
7.13.3
HF-Wavefunctions............................................................................................347
7.13.4
Non-Hybrid DFT..............................................................................................347
7.13.5
Hybrid DFT......................................................................................................349
7.13.6
Doubles Correction..........................................................................................349
7.13.7
Computational Aspects.....................................................................................351
7.13.7.1
RI approximation (AO-basis).......................................................................................................351
7.13.7.2
RI approximation (MO-basis)......................................................................................................351
7.13.7.3
Integral Handling.........................................................................................................................352
7.13.7.4
Valence versus Rydberg states.....................................................................................................352
7.13.7.5
Asymptotatically Corrected Density Functionals........................................................................353
7.13.7.6
Potential Energy Surface Scans...................................................................................................356
7.13.7.7
Potential Energy Surface Scans along Normal Coordinates........................................................357
7.13.7.8
Normal Mode Scan Calculations Between Different Structures..................................................361
7.14
THE MULTIREFERENCE CORRELATION MODULE...................................................363
7.14.1
General Description of the Correlation Module..............................................363
7.14.2
The SOC Submodule of the MRCI Module....................................................367
7.14.2.1
Calculation of the Spin-Spin Coupling and Spin-Orbit Coupling and Effects............................367
7.14.2.2
Magnetic fields in MRCI.............................................................................................................375
7.14.2.3
g-tensor calculations.....................................................................................................................376
7.14.2.4
Relativistic Picture Change in Douglas Kroll SOC and Zeeman operators.................................377
7.14.2.5
MCD and Absorption Spectra Calculation and Generation.........................................................378
Orca Version 2 - Input Description 8
7.15
SIMULATION AND FIT OF VIBRONIC STRUCTURE IN ELECTRONIC SPECTRA, RESONANCE
RAMAN EXCITATION PROFILES AND SPECTRA WITH THE ORCA_ASA PROGRAM...................382
7.15.1
General Description of the Program................................................................383
7.15.2
Spectral Simualtion Procedures: Input Structure and Model Parameters.......384
7.15.2.1
Example: Simple Model...............................................................................................................384
7.15.2.2
Example: Modelling of Absorption and Fluorescence Spectra within the IMDHO Model........386
7.15.2.3
Example: Modelling of Absorption and Fluorescence Spectra within the IMDHOFA Model...389
7.15.2.4
Example: Modelling of Effective Broadening, Effective Stokes Shift and Temperature Effects in
Absorption and Fluorescence Spectra within the IMDHO Model.....................................................................390
7.15.2.5
Example: Modelling of Absorption and Resonance Raman Spectra for the 1-1A →1-1B Transition in 1,3,5
g u
trans-hexatriene..................................................................................................................................................393
7.15.2.6
Example: Modelling of Absorption spectrum and Resonance Raman Profiles for the 1-1A →1-1B
g u
Transition in 1,3,5 trans-hexatriene...................................................................................................................397
7.15.3
Fitting of Experimental Spectra.......................................................................399
7.15.3.1
Example: Gauss-Fit of Absorption Spectrum..............................................................................399
7.15.3.2
Example: Fit of Absorption and Resonance Raman Spectra for 1-1A →1-1B transition in 1,3,5 trans-
g u
hexatriene 406
7.15.3.3
Example: Single-Mode Fit of Absorption and Fluorescence Spectra for 1-1A →1-1B transition in
g 2u
Tetracene 413
7.15.4
Quantum-Chemically Assisted Simulations and Fits of Optical Bandshapes and
Resonance Raman Intensities.........................................................................................417
7.15.4.1
Example: Quantum-Chemically Assisted Analysis and Fit of the Absorption and Resonance Raman Spectra
for the 1-1A →1-1B Transition in 1,3,5 trans-hexatriene.................................................................................418
g u
7.15.4.2
Important Notes about Proper Comparison of Experimental and Quantum Chemically Calculated
Resonance Raman Spectra.................................................................................................................................426
7.15.4.3
Example: Normal mode scan calculations of model paramters for 1-1A →1-1B transition in 1,3,5 trans-
g u
hexatriene 428
7.16
THE COSMO SOLVATION MODEL........................................................................430
7.17
CALCULATION OF PROPERTIES..............................................................................433
7.17.1
Electric Properties............................................................................................433
7.17.2
The Spin-Orbit Coupling Operator..................................................................433
7.17.3
The EPR/NMR Module.....................................................................................436
7.17.3.1
Hyperfine and Quadrupole Couplings.........................................................................................437
7.17.3.2
The g-tensor.................................................................................................................................440
7.17.3.3
Zero-Field-Splitting......................................................................................................................441
GENERAL TREATMENT........................................................................................................443
7.18
POPULATIONS ANALYSIS AND CONTROL OF OUTPUT.............................................450
7.18.1
Controlling Output...........................................................................................450
Orca Version 2 - Input Description 9
7.18.2
Mulliken Population Analysis...........................................................................452
7.18.3
Löwdin Population Analysis.............................................................................453
7.18.4
Mayer Population Analysis..............................................................................454
7.18.5
Natural Population Analysis............................................................................455
7.18.6
UNO Orbital Printing.......................................................................................460
7.19
ORBITAL AND DENSITY PLOTS...............................................................................460
7.19.1
Contour Plots....................................................................................................460
7.19.2
Surface Plots.....................................................................................................462
7.19.2.1
General Points..............................................................................................................................462
7.19.2.2
Interface to gOpenMol.................................................................................................................464
7.19.2.3
Interface to Molekel.....................................................................................................................465
7.20
UTILITY PROGRAMS...............................................................................................466
7.20.1
orca_mapspc.....................................................................................................466
7.20.2
orca_chelpg......................................................................................................467
7.20.3
orca_pltvib........................................................................................................467
7.20.4
orca_vib............................................................................................................468
7.20.5
orca_plot...........................................................................................................468
7.20.6
orca_2mkl: Old Molekel as well as MolDen inputs.........................................468
7.20.7
orca_vpot..........................................................................................................469
8
SOME TIPS AND TRICKS (UPDATED DECEMBER 2009)................................469
8.1
COST VERSUS ACCURACY.........................................................................................469
8.2
CONVERGING SCF CALCULATIONS...........................................................................473
8.3
CHOICE OF THEORETICAL METHOD..........................................................................474
9
LITERATURE..............................................................................................................477
SUMMARY OF REVISIONS............................................................................................480
Orca Version 2 - Input Description 10
Foreword
The
ORCA
project
is
now
almost
10
years
old
and
it
is
probably
fair
to
say
that
the
program
has
significantly
matured
over
the
past
years.
It
is
now
used
by
almost
4000
individuals
or
research
groups
and
is
installed
at
dozens
if
not
hundreds
of
supercomputer
centers
worldwide.
We
feel
strongly
encouraged
by
this
fact
and
it
is
our
pleasure
to
further
develop
the
program
for
the
benefit
of
the
computational
chemistry
and
spectroscopy
communities.
Since
2006
when
the
group
moved
to
the
university
of
Bonn,
there
has
been
a
gradual
shift
in
the
focus
of
the
development
from
special
spectroscopy
to
more
general
purpose
quantum
chemistry.
This
was
made
possible
because
the
development
group
has
considerably
grown
and
highly
talented
and
motivated
students
continued
to
bring
in
new
features
in
and
greatly
improved
existing
ones.
The
areas
that
are
perhaps
most
active
in
future
developments
concern
simplified
wavefunction
methods
or
the
single
reference
type
(MP2
and
local
coupled
pair/coupled
cluster
methods)
and
new
density
functionals
(in
particular
double
hybrid
functional).
An
area
that
will
see
more
activity
in
the
future
is
multireference
theory.
However,
with
all
developments
in
improved
wavefunctions,
a
focus
of
the
program
will
remain
theoretical
spectroscopy
and
we
plan
to
further
enhance
the
programs
capabilities
in
this
area.
Finally,
performance,
parallelization
robustness
and
user
friendliness
are
subjects
that
are
high
on
our
priority
list.
As
always,
we
appreciate
positive
as
well
as
negative
feedback
from
our
growing
group
of
users
and
hope
that
you
enjoy
using
the
program
as
much
as
we
enjoy
developing
it.
As
ORCA
is
strictly
non-‐commercial
you
can
count
on
the
fact
that
it
will
remain
free
of
charge.
The
best
way
to
show
your
appreciation
of
our
efforts
is
to
cite
our
original
research
and
development
papers
in
your
own
work.
This
will
provide
us
with
the
possibility
of
raising
sufficient
funding
for
continuing
to
do
what
we
enjoy
most
–
develop
quantum
chemistry!
Frank
Neese,
December
2009
Description:University of Bonn, 2010. — 489 p. Version 2.8-20 September 2010Manual for Quantum Chemistry computational package ORCA. ORCA package is free of charge and can be installed on all computation facilities.This manual provides a description and explanation on how to set up Ab initio, HF, DFT, TD-DFT,
