I know GAMESS is not best suited for crystal simulation but I am not ready to start learning another package as VASP. As I heard GAMESS is able to do some calculations in a "terminated" crystal (I mean using an ion in the periphery instead of repeating it multiple times). Mostly I need to calculate HOMO-LUMO gap / hessian matrix and transitional state of a surface reaction .

I looked in the web but couldn't find a good worked example of using GAMESS for crystals. Is there anywhere I can find such an example ?


1 Answer 1


As you said, there are many packages capable of handling calculations of crystals, slabs, etc. with periodic boundary conditions. VASP is only one of dozens. (That's probably a separate question in its own right.)

GAMESS does not include treatment of periodic boundary conditions, so you would need to run a calculation on a "cluster."

Since you mention wanting to treat a surface reaction, you'd use a builder (e.g., Avogadro) to create a large cluster (e.g., Build->Supercell). So rather than one primitive unit cell, you create maybe a 2x2x2 or 3x3x3 slab. If needed, you'll terminate dangling bonds (e.g., adding hydrogens to cap oxygens in $\ce{TiO2}$ for example.. notice the terminal "uncapped" atoms on the back and right of the unit cell).

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Finally, after running calculations in GAMESS, you'd need to check for convergence. So you'd want to run calculations with increasing system size and see if the properties converge.

Now, this isn't as strange as it sounds. In some cases ($\ce{MgO}$ and $\ce{TiO2}$ are good examples) the properties require more advanced calculation methods like multi-configuration QM, and this may be easier to do in a quantum chemical package with a cluster, rather than a solid-state crystal code.

  • $\begingroup$ Thank you Geoff. I am yet struggling with that Hydroxyapatite crystal! As you suggested in another question, I found a decent .cif file for it in COD( thank you for the suggestion !). I opened it with Avogadro and next step is normally finding a good geometric start point, and I ran UFF optimization but the whole crystal system burst ! I don't know how should I avoid such a heavy energy that destroys the whole system. Here is the file: crystallography.net/cod/9011091.html?applet=jmol $\endgroup$
    – Aug
    Commented Mar 11, 2015 at 18:31
  • $\begingroup$ I forgot to mention that I made a 3x3x1 supercell before running the UFF. $\endgroup$
    – Aug
    Commented Mar 11, 2015 at 18:39

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