Questions tagged [mrcc]
For questions about (or involving) the MRCC electronic structure software package.
11
questions
2
votes
1
answer
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MRCC/CFOUR interface bug for a single atom calculation?
I am trying to run the calculation of the DBOC using CFOUR/MRCC interface for a single atom. The calculation runs with no issues without MRCC (i.e. if CC_PROG=MRCC is removed from the ZMAT file below),...
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5
votes
0
answers
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Core-valence separation (CVS) keyword in MRCC program [closed]
I am interested in using the CVS option in CI calculations to get core-excited states. I tried to use the MRCC program which possesses this option according to the manual (cvs=...). I performed some ...
- 191
8
votes
1
answer
201
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Interfacing MRCC with CFOUR for dynamic polarizability
I have asked this question on the MRCC forum but did not get an answer.
I am trying to understand how to use CFOUR with the MRCC program for computing dynamic polarizability. To begin with, I am ...
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5
votes
1
answer
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ssr functional for the dft=userd in MRCC package
I found the nice userd example with the standard functional in the latest MRCC manual but I wonder if one can also use ssr (...
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4
votes
1
answer
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Crash of DF-CCSD or DF-CCSD(T) geometry optimization (MRCC package)
I am interested in geometry optimization at the CCSD(T) or DF-CCSD(T) level, with MRCC.
The calculation, however, crashes when executing prop:
...
- 33.6k
4
votes
1
answer
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Which programs can calculate corrections to the Born-Oppenheimer approximation?
I need to calculate the electric dipole moment of molecules like HD, in which the electric dipole moment is zero in the Born-Oppenheimer approximation (meaning that it's absolutely necessary to ...
- 33.6k
17
votes
3
answers
781
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How is "basis set projection" done?
I recently came across something called the basis set projection in Q-chem's manual. What it seems to do is to take the converged SCF in a smaller basis set, and then "projects" that onto a ...
- 33.6k
9
votes
2
answers
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What are Pair Natural Orbitals?
Recently, I came across electron correlation methods that use local pair natural orbitals (LPNOs) or domain-based local pair natural orbitals (DLPNO), such as DLPNO-MP2, DLPNO-CCSD etc. The dynamic ...
- 33.6k
11
votes
2
answers
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Analytic gradient for DLPNO-CCSD
Is there a formula for analytical gradients (for geometry optimization) for the DLPNO-CCSD method? I ask because I know that it is not implemented in ORCA. Maybe PNO-CCSD is implemented in MRCC or ...
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16
votes
3
answers
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How to calculate homolytic bond dissociation energies?
An experimental colleague asked me how hard it would be to calculate homolytic bond-dissociation energies for different phosphonates which are involved in a Hydrophosphination. The compounds include ...
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20
votes
3
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What is the largest system that has been studied by the coupled cluster method?
This is parallel to the analogous question about the largest DFT calculation: What is the largest material that has been studied using density functional theory?
I assume we allow high performance ...
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