Hi

I am not sure about Gamess, but for Gaussian there are a few basic things that you should consider.

First, laptops are not ideal to run calculations intensively. You can do it, but you will probably reduce significantly the lifetime of the laptop. If you just want it to run short calculations from time to time then there shouldn't be a problem.

Then you need to consider which version of Gaussian you have available. Note that Windows versions of Gaussian09 and earlier versions are capped! Gaussian09W cannot run calculations with more than 4 cores and 2GB RAM memory (ca. 1.5 GB in practice). Consequently, if you are planning to use Gaussian09 you should buy a laptop with a standard processor with 4 cores (try to find good cores, e.g. you can check the cpu benchmark online) and a standard RAM memory (i.e. 8 or 16 GB).

On the other hand, the Windows version of Gaussian16 is not capped, so you can go for more powerful configurations (more cores and memory). This would allow you to calculate bigger molecules and use better levels of theory. Note that frequency calculations are very memory demanding, so try to get as much RAM memory as possible (at least 32 GB).

Raw power (i.e. cores and memory) is the main requirement to run these calculations, so try to get as much as you can with this budget. As a personal opinion, I would try to avoid posh brands (Apple, etc.) as you will end up paying more for less raw power.

Hope this helps. Good luck!

Martí

thank you for you helpful suggestions. iI may need to think about building up a desktop。

no problem.just go to shop and buy it.