brucefan1983/GPUMD: GPUMD-v3.4

Removed Removed a few empirical potentials (Vashishta, SW, REBO-LJ, and Buckingham-Coulomb) and removed the hybrid-potential scheme. For those who want to use these features, GPUMD-v3.3.1 will be the best choice. Removed the neighbor keyword in run.in. The code will build the neighbor list at each step with the potential cutoff. The user does not need to estimate a neighbor list size now. For NEP models, the information of neighbor list size will be recorded into nep.txt. For empirical potentials, the code has chosen reasonable neighbor list sizes. There will not be a list of atom types (integers) after the potential filename for the potential keyword. Removed the so-called "driver input file" for both the gpumd and nep executables. Changed Changed xyz.in to model.xyz, and changed train.in/test.in to train.xyz/test.xyz. All the .xyz files are in the extended XYZ format. See the manual pages https://gpumd.zheyongfan.org/index.php/The_model.xyz_input_file and https://gpumd.zheyongfan.org/index.php/The_train.xyz_input_file for details on the extended XYZ format. Added Added multi-GPU (single-node) support for both training and MD simulation with the NEP model. The code will use all the GPUs available. The available GPUs can be set by running e.g. export CUDA_VISIBLE_DEVICES=0,1 (0 and 1 are the IDs of the GPUs to be used) in the command line or by specifying something in a job-submission script in a cluster