Questions tagged [psi4]
For questions about using the Psi4 Quantum Chemistry Package.
12
questions
18
votes
1
answer
333
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Exchange-Correlation Two-Electron Integrals
Do any freely available or proprietary electronic structure packages explicitly compute two-electron exchange correlation integrals?
I have found a few derivations to calculate excited state ...
- 15k
17
votes
1
answer
702
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Alternatives to VEDA 4 vibrational energy distribution analysis software?
Said software is useful when you need to assign the peaks in vibrational spectra to different vibrational modes found in a hessian calculation for a given molecule, as described in Jamróz, Michał H. “...
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9
votes
2
answers
499
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What do the indices mean in an FCIDUMP file?
I generated an FCIDUMP file, which is copied below
...
- 231
9
votes
1
answer
427
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Error running psi4 on charged molecules
I am running a simple energy calculation on a conformer of 3-Sulfopropyl methacrylate, which is given my C=C(C)C(=O)OCCCS(=O)(=O)[O-].
This is my workflow:
...
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8
votes
2
answers
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How do I figure out how many monomer configurations I need for my simulation?
I am running a quantum mechanical simulation on Psi4 for a certain number of monomers to generate data for a database. Some of these monomers are short, while some are long.
At the moment, I am ...
- 4,141
7
votes
1
answer
231
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Computing analytic derivatives of molecular Hamiltonians obtained from solving Hartree-Fock equations
I'm currently working on a quantum chemistry project, I am dealing with a second-quantized electronic Hamiltonian (corresponding to some molecule), written in terms of fermionic creation and ...
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5
votes
1
answer
180
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Calculating first and second derivatives of a molecular Hamiltonian?
I'm interested in computing first and second derivatives of molecular Hamiltonians with respect to nuclear coordinates. I've been using Psi4 and PySCF to perform Hartree-Fock calculations, and I was ...
- 409
3
votes
1
answer
77
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Decay rate of DSD-PBEPBE-D3BJ
I gave up on the wB97X-2(TQZ) functional, which would have an exact decay rate of -1/r, re: my previous question and decided to use DSD-PBEPBE-D3BJ, which is available on vanilla Psi4. I then looked ...
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3
votes
1
answer
76
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Psi4 Takes too Long to Save Computation Results to Python Notebook
I was using psi4 to run vibrational frequency analysis with small molecules (in a jupyter notebook) and it works just fine with molecules like methanol and water but once I move up to ethanol or ...
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3
votes
1
answer
77
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PSI4 SAPT calculation: failure to write
I am attempting to run SAPT0 calculations on dimer complexes with around 100 atoms each. However, PSI4 SAPT0 calculations freeze and get terminated with the following error messages - I assigned 48GB ...
- 233
3
votes
1
answer
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Psi4 functionnals: LDA0
When comparing the energy of the LDA0 and SVWN (Slater exchange and VWN(1980) correlation), I get different results.
So what is the LDA0 functional in Psi4? I can't really find literature about it.
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1
vote
1
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How do I install the beta5 version of PSI4 on my WebMO Basic server?
Installing the basic version of PSI4 on my personal LG Gram 360 (with a Windows OS), used as a my-own WebMO Basic server, was done according to the WebMO tutorial. I then tried to compute the energy ...
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