12
votes
Accepted
Analytic gradient for DLPNO-CCSD
Note that the DLPNO method is only implemented in ORCA. There are indeed analogous and similarly efficient and accurate methods, the PNO-LCCSD method in Molpro [doi.org/10.1021/acs.jctc.7b00799] and ...
- 206
12
votes
What significant matter modelling methods are implemented in commercial software, for which there is no freeware alternative?
I think the way this question is asked is a little too simplistic. In order to execute a computational project, there is always more than one calculation required. Even if you are happy with the ...
- 274
11
votes
Accepted
How to calculate homolytic bond dissociation energies?
Multi-reference or single-reference?
While it is appreciated that near dissociation there will be a near-degeneracy of orbitals, requiring a multi-reference treatment, fortunately we don't have to ...
- 33.6k
11
votes
Accepted
Can MOLPRO (2012) calculate SA-CASSCF gradients with cc-pVDZ?
The MOLPRO 2012.1 manual is no longer online, although there is an archive of at least some of the pages and you can try your luck for finding the pages you want on the archive, but it might not be ...
- 33.6k
11
votes
Accepted
Is it possible to do TD-DFT/6-31G+(d,p) calculations on a laptop?
Basis set name versus number of total orbitals
I would like to first address a part of the question that appears to be a misconception about the use of a 6-31+G(d,p) basis set, since you wrote:
"...
- 33.6k
10
votes
Accepted
How to interpret molden AO/MO coefficients?
Okay, so there are many layers to this question. cc-pVTZ for H is [5s2p1d/3s], which comes out to 3 + 2*3 + 5 = 3+6+5 = 14 basis functions per atom, which are composed of 16 primitives (the contracted ...
- 18k
8
votes
What significant matter modelling methods are implemented in commercial software, for which there is no freeware alternative?
One can also pose the opposite question, which may be more interesting: what significant matter modelling methods are implemented in open source software, for which there is no commercial alternative? ...
- 18k
8
votes
How to calculate homolytic bond dissociation energies?
BDEs are calculated by the below procedure:
Calculate initial energy
Perform homolytic bond cleavage and separate fragments
Calculate energies of the fragments, add the energies together
Calculate ...
- 1,526
8
votes
Analytic gradient for DLPNO-CCSD
As far as I know, analytic gradients for DLPNO-CCSD are not available in ORCA. Analytic first derivatives are available for both closed-shell and high-spin open-shell cases, which could be used for ...
- 196
7
votes
Choosing an active space for CASSCF using Molpro
As a developer of MOKIT, I would like to recommend the automatic CASSCF computation using the automr utility in MOKIT. We do not need to manually choose/permute ...
- 646
6
votes
Accepted
What do the parameters at the top of an FCIDUMP file mean?
MS2 is related to the spin. Specifically, it is the number of unpaired electrons. Your molecule is a singlet, which is why it says ...
- 33.6k
6
votes
Choosing an active space for CASSCF using Molpro
First of all, your syntax isn't exactly the way the MOLPRO manual for the CASSCF program (called "Multi") instructs:
OCC,n1,n2,…,n8;
CLOSED,n1,n2,…,n8
...
- 33.6k
6
votes
How to calculate homolytic bond dissociation energies?
One thing the other answers haven't mentioned is the zero point and thermal corrections to the BDE.
As mentioned in the Wikipedia Morse potential article, a geometry optimization will take you, by ...
- 9,045
6
votes
Interface between PySCF and Molpro
Interoperability between quantum chemistry packages is almost non-existent when it comes to more complicated data structures, and there is no real standard for wavefunction or density matrix ...
- 385
6
votes
Understanding the difference between Dunning and Karlsruhe basis sets
The definition of fast and slow is a bit complicated.
I just tried an organic molecule with about 100 atoms and ran two jobs: One with def2-TZVP (1647 AO basis sets, 1872 CAOs) and one with cc-pVTZ (...
- 116
6
votes
Understanding the difference between Dunning and Karlsruhe basis sets
What systems are you running? Turbomole is designed for basis sets employing segmented contractions (like the Karlsruhe sets are), whereas the Dunning sets are generally contracted.
While any code ...
- 18k
5
votes
How are one-/two- particle reduced density matrices printed in mainstream programs?
1RDMs are just simple matrices, which can be stored in either dense or sparse form, possibly combined with triangular storage (the matrix is often symmetric). 1RDMs are passed around in a number of ...
- 18k
5
votes
MOLPRO: is there an analogue of the Gaussian FCHK file?
Following the HORTON information webpage about supported data file formats from section 2.4.3. Wavefunction formats (using a Gaussian basis set):
...
- 22.3k
4
votes
Accepted
How to determine occupied and closed orbitals for a Molpro CASSCF calculation?
The occupied orbital pattern of 13 7 6 2 that you got from your Hartree-Fock calculation is not unique. For example, I've just run an RHF calculation on PdO with ...
- 33.6k
4
votes
Correlation tables between irreps for f orbitals
The simplest way to check the correlation between $f$-type basis functions in a high-symmetry point group (say $D_{\infty h}$) and in its Abelian subgroup (say $D_{2h}$) or any other subgroup is to ...
3
votes
Accepted
In Molpro, how to calculate the orbital angular momentum?
"However they are listed with parity -1, and: "Expectation values are
only nonzero for symmetric operators (parity=1)"."
This matches the ...
- 33.6k
3
votes
In Molpro, how do I get the two-electron operator for angular momentum from a CI calculation?
In the first sentence of this Introduction to MOLPRO, MOLPRO is described as a "system of programs", not just one program.
The first link you provided is for the program called ...
- 33.6k
3
votes
How does MOLPRO choose active orbitals in a CASSCF calculation?
You fixed the occupation within symmetries by the command "occ,6,3,3,2" and asked the program to make CASSCF for the lowest 5 singlet states of symmetry 1 ...
- 39
3
votes
Accepted
Interface between PySCF and Molpro
So what I originally wanted is possible, with a little python scripting.
To achieve this, a fcidump file containing h1 and h2 needs to be created by moplro.
This entails running an SCF in molpro ...
- 489
1
vote
Excited states of Lithium in MOLPRO
The author of the question found a solution:
"Hi Andrea and Tyberius, sorry for the late reply, my problem is already solved, thank you!"
If anyone (including the author of the question) ...
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