Gaussian 03 can perform energy minimization by applying various basis sets like DFT/B3LYP level 19 and using the cc-pVDZ. Which other free software can carry out similar types of optimization?
It is a standard functional included in virtually any general-purpose software. You can use US-Gamess, Orca, or NW-Chem, for example.
Mr. Patil, Dalton 2011 is very useful free of charge quantum chemical software (under Linux).
For energy optimization using different basis sets you can also use CPMD, which a free software.
http://www.cpmd.org/
cc-pVDZ is one of the worst choices for the geometry optimization. It has a very large superposition error.
DFT methods are much less sensitive to basis set than ab initio, so it is well possible that the B3LYP/cc-pVDZ optimization will lead to a decent geometry. But of course it depends on the particular case.
Oh, I'd recommend Dalton as well but I used to think that it is a purely ab initio program. Cool thing is that they keep releasing new versions; the last one is Dalton2013.
There are a number of software available, working for molecules as well as for polymers, crystals, slabs etc.
you have GAMES-US, NWChem for molecule systems, Abinit, Siesta, QuantumExpresso for periodic systems, for example.
I have tried many of these. My objective in using these software is to assign charges to the atoms of molecules for MD simulation. PRODRG serves assigns such charges but I wanted to generate them from QM calculations with user defined parameters. I found Arguslab software best for me as it is very easy to use. Though other softwares mentioned above work well, I am unable to use them with GUI. Thanks anyway for all the suggestions which helped me succeed in calculating desired charges.
PC GAMESS and NWChem calculate potential derived charges well. And it can be done under GUI: http://www.biomolecular-modeling.com/Products.html
If you study biomolecules, the RED program might be useful for you http://q4md-forcefieldtools.org/RED/. It is compatible with GAMESS.
What about Ascalaph program which has almost all interfaces like PC GAMESS, NWChem. Currently I am not studying biomolecules, rather I am building a QM optimized model for the ligands. I want to load the charges derived from such optimization later in to MD simulations. I am not well versed with command line usage for most of these software and in fact I could not able to install them in windows. Though I work in Ubuntu 12.0 for MD, I prefer installations only through Sunaptic package manager. I found Firefly PC Gamess, Argus lab (only C, H, N, S, Cl, O atoms supported) & Ascalaph handy , I will try RED as well meanwhile.
Ascalaph has linux version. Unfortunately it's old 1.1.4. However, it should work with PC Gamess (but not with Firefly).
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