vasp-ase

name	vasp_ase
description	Professional skill for setting up, executing, and debugging VASP DFT calculations using the Atomic Simulation Environment (ASE).
version	1.0.0

VASP ASE Skill

This skill allows the agent to interface with VASP on high-performance computing (HPC) systems like the DGX A100. It focuses on using ASE as the wrapper for clean Pythonic control.

🛠 Prerequisites

• Environment Variables: VASP_PP_PATH must point to the directory containing potpaw_PBE, etc.
• Dependencies: ase and pymatgen (optional but recommended for analysis) must be installed in the (base) conda environment.
• VASP Executable: Access to vasp_std, vasp_gam, or vasp_ncl.

📜 Execution Instructions

1. Setup & Initialization

Always initialize the VASP calculator using the ase.calculators.vasp.Vasp class.

• Default Check: If the user doesn't specify, use xc='PBE', kpts=(4, 4, 4), and encut=520.
• Parallelization: On this DGX system, use mpirun or srun. Example command: command='mpirun -np 16 vasp_std > vasp.out'

2. Geometry Optimization Template

from ase.io import read
from ase.calculators.vasp import Vasp
from ase.optimize import BFGS

atoms = read('POSCAR')
calc = Vasp(directory='run_dir',
            command='mpirun -np 16 vasp_std',
            xc='PBE',
            encut=520,
            ismear=0,
            sigma=0.05,
            lreal='Auto',
            nsw=100,
            ibrion=2)
atoms.set_calculator(calc)
energy = atoms.get_potential_energy()

3. Error Handling & Troubleshooting

If a calculation fails, the agent should parse OUTCAR or stdout and apply these fixes:

Error/Issue	Diagnostic	Fix Strategy
Electronic Convergence	NELM reached without dE < ediff	Set ALGO = Normal or Fast; increase NELM to 100; try AMIX = 0.2.
Ionic Convergence	Max steps reached	Restart from the last CONTCAR; check if forces are oscillating.
Memory/A100 Crash	Segmentation fault	Reduce NCORE or KPAR; ensure LREAL = Auto.
Missing POTCAR	RuntimeError: POTCAR not found	Verify VASP_PP_PATH is exported in ~/.bashrc.

🧪 Validation Step

Before running large productions, the agent should run a "Dry Run" by setting LSTOP = .TRUE. in the INCAR or running a single-point energy on a 2-atom cell to verify the environment pathing.

📂 Output Management

• Always capture energy_free, forces, and stress.
• Store results in a structured JSON or CSV for the user to download from the DGX server.