ABINIT

When to Use

• User explicitly requests ABINIT
• User needs DFPT (density-functional perturbation theory) phonons natively
• User needs GW quasiparticle calculations or BSE optical spectra
• User wants multi-dataset calculations in a single input file

Prerequisites

1. ABINIT binaries accessible on HPC (abinit --version)
2. Pseudopotentials available (JTH PAW or PseudoDojo NC recommended)
3. Structure loaded in viewer — verify with catgo_view(action="get_state")

Workflow Steps

1. Verify structure

catgo_view(action="get_state")

2. Create workflow

catgo_workflow_engine(action="create", params={"name": "ABINIT GW band gap"})

3. Add ABINIT task via shell

CatGo does not yet have a native ABINIT engine. Use task_type: "shell".

catgo_workflow_engine(action="add_task", params={
  "workflow_id": "wf_xxx",
  "task_type": "shell",
  "name": "abinit_scf",
  "command": "abinit < abinit.files > abinit.log 2>&1",
  "input_files": {
    "abinit.in": "<input content>",
    "abinit.files": "<files file content>"
  },
  "system_name": "Si_GW"
})

When a @register_engine("abinit") is added, use task_type: "geo_opt" with software: "abinit".

Input File Template — SCF

# SCF ground state
ndtset 1

# System
natom  <natoms>
ntypat <ntypes>
typat  <type_list>
znucl  <Z_list>

acell  3*1.0
rprim
  <a1x> <a1y> <a1z>
  <a2x> <a2y> <a2z>
  <a3x> <a3y> <a3z>

xred
  <x1> <y1> <z1>
  <x2> <y2> <z2>

# Plane-wave basis
ecut    40.0    # Ha (= 2x Ry)
pawecutdg 80.0  # PAW fine grid

# K-points
ngkpt   <k1> <k2> <k3>
nshiftk 1
shiftk  0.0 0.0 0.0

# SCF
nstep   100
toldfe  1.0d-8   # Ha

# Smearing
occopt  3        # Fermi-Dirac
tsmear  0.002    # Ha (~0.05 eV)

# XC
ixc     11       # PBE

The .files File

ABINIT uses a .files file listing input/output/pseudo paths:

abinit.in
abinit.out
abiniti
abinito
abinit_tmp
pseudo/Si.paw

Lines: input, output, root_input, root_output, tmp_dir, then one pseudo per atom type.

Parameter Guidance

Parameter	Typical value	Notes
ecut	30-50 Ha	In Hartree (1 Ha = 27.2 eV); check pseudo recommendations
pawecutdg	2x ecut	PAW augmentation grid; only for PAW pseudos
toldfe	1.0d-8	Energy convergence in Ha
toldff	1.0d-5	Force convergence in Ha/Bohr (for relaxation)
ngkpt	auto from cell	Monkhorst-Pack grid
occopt	3 (FD) or 7 (Gaussian)	Smearing type
ionmov	2 (BFGS)	Ion relaxation algorithm
optcell	0 (ions) / 2 (full)	Cell optimization level

Multi-Dataset Calculations

ABINIT supports chaining calculations in one input via ndtset:

ndtset 3

# Dataset 1: SCF
toldfe1 1.0d-8

# Dataset 2: NSCF for DOS
iscf2    -2
tolwfr2  1.0d-12
getden2  1

# Dataset 3: DFPT phonons
rfphon3  1
nqpt3    1
qpt3     0.0 0.0 0.0
toldfe3  1.0d-10
getden3  1
getwfk3  1

Common Pitfalls

1. ecut in Hartree, not eV — ABINIT uses Hartree (1 Ha = 27.2 eV). A 40 Ha cutoff is ~1088 eV.
2. Coordinates default to reduced (xred) — use xred (fractional) or xcart (Bohr). Not Angstrom.
3. Missing .files file — ABINIT reads file paths from stdin or a .files file; forgetting it causes silent failure
4. PAW augmentation grid — if using PAW pseudos, pawecutdg must be set (typically 2x ecut)
5. GW convergence — GW calculations need many empty bands (nband) and careful ecuteps convergence
6. Large tmp files — ABINIT writes wave functions to _TMP; ensure sufficient disk space