abacustest-abacus2vaspqecp2k

name	abacustest-abacus2VaspQeCp2k
description	Batch convert ABACUS input files to VASP/QE/CP2K formats. Use when: user wants to convert ABACUS calculations to other software, including both structure (STRU→POSCAR) and input parameters (INPUT→INCAR/pw.inp).
metadata	{"openclaw":{"emoji":"🔄","requires":{"pip":["abacustest"]}}}

abacustest Convert

Batch convert ABACUS input files (STRU + INPUT + KPT) to VASP, QE, or CP2K formats.

When to Use

✅ Use this skill: Batch convert ABACUS inputs to VASP/QE/CP2K for cross-software comparison

❌ Do not use: Extract results (abacustest-extract-dft-results)

Command

abacustest prepare -p param.json -s output_dir

Note: Conversion uses abacustest prepare command with specific parameters in param.json.

---

⚠️ Limitations: Parameter Conversion

Different software have different input parameters - not all parameters can be automatically converted.

• What can be converted: Common parameters (calculation type, cutoff, k-points, spin, etc.)
• What cannot be converted: Software-specific parameters (mixing schemes, advanced algorithms, etc.)
• Unconverted parameters: Will be printed to screen during execution for your reference

Recommendation: After conversion, manually review the generated files and add/adjust parameters as needed.

Conversion: ABACUS → VASP

Convert ABACUS input files to VASP format (INCAR, POSCAR, KPOINTS, POTCAR).

⚠️ Before You Start: Pseudopotential Library

Question: Do you have a VASP pseudopotential library (e.g., PAW_PBE, POTCAR files)?

• Yes: Provide the path (e.g., /path/to/vasp/PAW_PBE)
• No: POTCAR will NOT be automatically configured; you need to prepare it manually

Note: ABACUS uses norm-conserving pseudopotentials, while VASP uses PAW pseudopotentials. They are not directly compatible.

Configuration

Option 1: Using pseudopotential library (recommended)

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2vasp": true,
    "potcar": "/path/to/vasp/PAW_PBE"
  }
}

Option 2: Manual POTCAR mapping

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2vasp": true,
    "potcar": {"Fe": "/path/Fe.pot", "C": "/path/C.pot"}
  }
}

Option 3: No POTCAR (manual preparation)

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2vasp": true
  }
}

Parameters

Parameter	Description	Example
abacus2vasp	Enable conversion	true
example_template	ABACUS input directories	["calc1", "calc2"]
potcar	POTCAR library path OR file mapping	"/path/PAW_PBE" or {"Fe": "Fe.pot"}
vasp_setting	Additional VASP INCAR parameters (dict, optional)	{"ENCUT": 500}

vasp_setting Details:

• Type: Dictionary (dict)
• Purpose: Additional/custom VASP INCAR parameter settings
• Location: Under prepare in param.json
• Default behavior: If not specified, abacustest automatically converts ABACUS INPUT parameters to VASP equivalents
• Override behavior: If a parameter is set in vasp_setting, it will override the automatically converted value

Example (full param.json structure):

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2vasp": true,
    "potcar": "/path/to/PAW_PBE",
    "vasp_setting": {
      "ENCUT": 500,      // Override automatic ENCUT conversion
      "ISMEAR": 0,       // Override automatic smearing setting
      "EDIFF": 1e-5      // Override automatic convergence threshold
    }
  }
}

Special Parameter: emax_coef

vasp_setting supports a special parameter emax_coef for automatic ENCUT calculation:

# How emax_coef works:
encut_recommended = max([POTCAR[i].ENCUT for i in all_elements])
ENCUT = emax_coef * encut_recommended

# Example: Fe (ENCUT=240.6 eV) + C (ENCUT=400.0 eV)
# encut_recommended = max(240.6, 400.0) = 400.0 eV
# If emax_coef = 1.3:
# ENCUT = 1.3 * 400.0 = 520.0 eV

ENCUT Priority (highest to lowest):

1. vasp_setting.ENCUT → Use explicit value directly
2. vasp_setting.emax_coef → Calculate: emax_coef × max(POTCAR ENCUT)
3. Not specified → Auto-convert: ecutwfc (ABACUS) × Ry2eV

Important Notes:

1. potcar as library path: abacustest will automatically find and configure POTCAR files from the VASP pseudopotential library based on elements in the structure.

2. potcar not provided: POTCAR will NOT be automatically configured. You need to prepare POTCAR files manually after conversion.

3. For ABACUS/VASP comparison:

   • Recommend NOT setting vasp_setting (use automatic conversion)
   • Or only set ENCUT to account for pseudopotential differences
   • See "Why Only Set ENCUT for Comparison?" section below

Why Only Set ENCUT for Comparison?

ABACUS uses norm-conserving pseudopotentials, VASP uses PAW pseudopotentials.

• PAW pseudopotentials are softer → VASP's kinetic energy cutoff is naturally lower than ABACUS
• Typical conversion: ENCUT_VASP ≈ ENCUT_ABACUS × 0.6~0.8
• Example: ABACUS ecutwfc=80 Ry (≈1088 eV) → VASP ENCUT=500-700 eV may be sufficient

Output

output_dir/
└── abacus_calc/
    ├── INCAR      # VASP parameters (auto-converted or from vasp_setting)
    ├── POSCAR     # Structure
    ├── KPOINTS    # K-point mesh (if KPT file exists)
    └── POTCAR/    # Pseudopotentials (if potcar provided)

Note on KPOINTS:

• If ABACUS uses kspacing: abacustest converts it to KSPACING in INCAR (no KPOINTS file generated)
  • Unit conversion: ABACUS kspacing is in 1/Bohr, VASP KSPACING is in 1/Å
  • Conversion: KSPACING (1/Å) = kspacing (1/Bohr) × 1.8897
• If ABACUS uses KPT file: abacustest generates a KPOINTS file with the same k-point mesh

Parameter Mapping (Automatic Conversion)

ABACUS	VASP	Note
calculation	IBRION	scf→-1, relax→2, cell-relax→3
ecutwfc	ENCUT	Ry→eV (auto-adjusted for PAW)
scf_thr	EDIFF	Auto: scf_thr/1e-2 (PW) or /1e-1 (LCAO)
kspacing	KPOINTS	K-point density
nspin	ISPIN	Spin polarization
mag	MAGMOM	Magnetic moments
dft_plus_u	LDAU	DFT+U settings

Note: If vasp_setting is specified, those parameters will use your values instead of automatic conversion.

---

Conversion: ABACUS → QE

Convert ABACUS input files to Quantum ESPRESSO format (pw.in).

Pseudopotentials

abacustest uses pseudopotentials defined in the ABACUS STRU.

• Pseudopotential files (.upf) from the ABACUS directory are copied to output_dir/abacus_calc
• The pw.in file references these pseudopotential files automatically
• Note: Ensure your ABACUS pseudopotentials are in UPF format (QE standard format)

---

Configuration

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2qe": true,
    "qe_setting": {...}  
  }
}

Parameters

Parameter	Description	Example
abacus2qe	Enable conversion	true
example_template	ABACUS input directories	["calc1"]
qe_setting	Additional QE input parameters (dict, optional)	See below

qe_setting Details:

• Type: Dictionary (dict) with nested structure matching QE input format
• Purpose: Additional/custom QE parameters
• Location: Under prepare in param.json
• Default behavior: If not specified, abacustest automatically converts ABACUS INPUT parameters to QE equivalents
• Override behavior: If a parameter is set in qe_setting, it will override the automatically converted value

Structure (matching QE namelists):

{
  "qe_setting": {
    "version": "7.0",           // Special parameter (see below)
    "control": {                // CONTROL namelist
      "calculation": "scf",
      "restart_mode": "from_scratch"
    },
    "system": {                 // SYSTEM namelist
      "ibrav": 0,
      "ecutwfc": 50,
      "ecutrho": 400
    },
    "electrons": {              // ELECTRONS namelist
      "conv_thr": 1e-8
    }
  }
}

Special Parameter: version

• Type: String
• Purpose: QE version number (e.g., "6.5", "7.0", "7.1")
• Why it matters: Different QE versions use different formats for certain parameters, especially DFT+U (Hubbard) settings

Example: DFT+U format changes by version:

# QE < 7.0 (old format):
Hubbard_U(1) = 5.3
Hubbard_alpha(1) = 0.0

# QE >= 7.0 (new format):
Hubbard_U(Fe-3d) = 5.3
Hubbard_alpha(Fe-3d) = 0.0

abacustest uses the version parameter to generate the correct format for your QE version.

Supported namelists in qe_setting:

• control - CONTROL namelist
• system - SYSTEM namelist
• electrons - ELECTRONS namelist
• ions - IONS namelist
• cell - CELL namelist
• Block definitions: "HUBBARD (ortho-atom)": ["U Fe1-3d 5.3"]

QE input parameter reference: https://www.quantum-espresso.org/Doc/INPUT_PW.html

Output

output_dir/
└── abacus_calc/
    ├── input      # QE input (pwscf format)
    └── *.upf      # Pseudopotentials (copied from ABACUS directory)

Conversion: ABACUS → CP2K

Convert ABACUS input files to CP2K format (input.inp).

Configuration

{
  "prepare": {
    "example_template": ["abacus_calc"],
    "abacus2cp2k": true,
    "cp2k_setting": {
      "GLOBAL": {
        "RUN_TYPE": "ENERGY_FORCE"
      },
      "FORCE_EVAL": {
        "DFT": {
          "SCF": {
            "EPS_SCF": 1e-6
          },
          "QS": {
            "EPS_DEFAULT": 1e-10
          }
        }
      }
    }
  }
}

Parameters

Parameter	Description	Example
abacus2cp2k	Enable conversion	true
example_template	ABACUS input directories	["calc1"]
cp2k_setting	CP2K input parameters	Nested dictionary

Note: cp2k_setting structure matches CP2K input format. Keys are section names, values are subsections or parameters.

Output

output_dir/
└── abacus_calc/
    └── input.inp  # CP2K input

Parameter Mapping

ABACUS	CP2K	Note
calculation	RUN_TYPE	scf→ENERGY_FORCE
ecutwfc (PW)	CUTOFF	×1000 (Ry→Ry)
ecutwfc (LCAO)	REL_CUTOFF	×100
scf_thr	EPS_SCF	SCF convergence
force_thr	RMS_FORCE	Force threshold

---

Common Errors

Error	Fix
POTCAR not found	Check potcar paths or use full path
Wrong ENCUT after conversion	Set emax_coef: 1.3 or define explicitly
QE version mismatch	Specify qe_setting.version
CP2K input format error	Verify cp2k_setting structure

Example: Cross-Software Benchmark

Goal: Compare ABACUS and VASP results for same structure

# 1. Run ABACUS calculation
# Directory: abacus-calc/ contains INPUT, STRU, KPT

# 2. Convert to VASP
cat > param.json << 'EOF'
{
  "prepare": {
    "example_template": ["abacus-calc"],
    "abacus2vasp": true,
    "potcar": {"Fe": "/path/Fe.pot"},
    "vasp_setting": {"ENCUT": 500, "EDIFF": 1e-5}
  }
}
EOF
abacustest prepare -p param.json -s vasp-calc

# 3. Run VASP calculation in vasp-calc/abacus-calc/

# 4. Compare results
abacustest collectdata -j abacus-calc -o abacus-result.json
abacustest collectdata -j vasp-calc/abacus-calc -o vasp-result.json

Best Practices

1. ✅ Verify POTCAR/pseudopotential compatibility
2. ✅ Check converted parameters (especially ENCUT)
3. ✅ Use same k-point density across software
4. ✅ Ensure DFT+U settings are equivalent
5. ✅ Validate structure integrity after conversion