An off topic question regarding Molecular Modeling

[JTM]

So I know there are a ton of really knowledgeable folks around here, and I've been on these forums for a bit, so I figured I'd start my search here.

I'm looking to model a few molecules and then manipulate them... aka, remove a proton and replace it with a charge and see how it changes and get the EMV from that cation, things like that.

It needs to be able to calculate lowest energy configurations.

Open source gets you bonus points

[Gopher]

Here is a link I found to a website from CMM and NIH. http://cmm.info.nih.gov/modeling/software.html

When I was an undergrad just a few years ago I used Spartan 02 and Gaussian 03 for my modeling and quantum needs. Sadly neither of these is open source, but they are both very very good programs. I found Spartan to be generally easier to work with but Gaussian to be more powerful, although I was not using Gaussview which is the graphical interface for Gaussian. As stated I was using old versions of both programs because that is what my adviser could afford. For the molecules I was studying (approximately 25C, 4N, 3O) It took about half a day in Spartan and 3-5 days in gaussian to do optimizations and excited state calculations on a pentium IV (optimizing in spartan and excited states in gaussian). In my research I also saw many papers saying they did their calculations in GAMESS.

[JTM]

awesome, this is what i needed. thanks!