Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with computational-chemistry
Search options not deleted
user 1380
For questions about computational chemistry.
8
votes
1
answer
909
views
Which basis set should be used for a system that contains both anions and cations?
I am trying to model a system that has both anions and cations interacting with each other. (In this case it is calcium ion interacting with two small carboxylic acid molecules). Now, looking through …
- 7,171
11
votes
2
answers
2k
views
Which methods are size-consistent / size-extensive, and why?
This is a follow up question from another question I posted here. I am looking for an explanation (or a mathematical proof, if possible) of the size extensivity and size consistency of the following c …
- 7,171
7
votes
Accepted
Computing optimized 3D structures in python that take solvent into account
From reading your comments, and the question, you want to generate optimized structures of small bioactive molecules in solvents, but it has to be fast. I would definitely recommend using semi-empiric …
- 7,171
15
votes
2
answers
510
views
Analytic Hessians for meta-GGA functionals
In many of the free/open-source QM programs like GAMESS, ORCA, NWChem, the calculation of analytic hessians is not possible when a meta-GGA density functional is used, like M06-2X. My first question i …
- 7,171
15
votes
2
answers
689
views
What is the difference between orbital localisation and NBO?
I am new to computational chemistry, I have used mainly GAMESS and Orca. In GAMESS, there are orbital localisation schemes like Pipek-Mezey, Ruedenberg-Edminston, etc. which generate orbitals that res …
- 7,171
8
votes
Running an ORCA calculation from Python
As the other answers and comments have suggested, the problem is probably coming from how Python is launching ORCA. Because I cannot see any reason the job should run from command line, but not from P …
- 7,171
7
votes
1
answer
332
views
What is the computational scaling of DFT energy vs gradient vs Hessian?
I am trying to understand the computational expense of calculating only the energy, versus the gradient/Hessian of the DFT energy with respect to nuclear coordinates. How do these scale with the size …
- 7,171
11
votes
2
answers
2k
views
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 el …
- 7,171