Revert "Add external DFTB+ backend scaffolding"

This reverts commit a08ad13.

Author: cheolhochoi

examples/DFTB/H2O_DFTBPLUS_GRADIENT.inp

@@ -2,7 +2,6 @@
 
 import oqp
 import oqp.library
-from oqp.library.dftbplus import run_openqp_molecule
 from oqp.library.single_point import (
     SinglePoint, Gradient, Hessian, LastStep,
     BasisOverlap, NACME, NAC
@@ -20,10 +19,6 @@
 
 
 def compute_energy(mol):
-    if mol.config['input']['method'] == 'dftb':
-        run_openqp_molecule(mol, gradient=False)
-        return
-
     # compute energy
     SinglePoint(mol).energy()
 
@@ -51,10 +46,6 @@ def compute_scf_prop(mol):
 
 
 def compute_grad(mol):
-    if mol.config['input']['method'] == 'dftb':
-        run_openqp_molecule(mol, gradient=True)
-        return
-
     # compute energy
     SinglePoint(mol).energy()
 

pyoqp/oqp/library/dftbplus.py

@@ -56,14 +56,6 @@ def path(strng):
         'system2': {'type': str, 'default': ''},
         'd4': {'type': bool, 'default': 'False'},
     },
-    'dftb': {
-        'executable': {'type': str, 'default': 'dftb+'},
-        'sk_path': {'type': str, 'default': ''},
-        'scc': {'type': bool, 'default': 'True'},
-        'max_scc_iterations': {'type': int, 'default': '100'},
-        'timeout': {'type': int, 'default': '300'},
-        'keep_workdir': {'type': bool, 'default': 'False'},
-    },
     'guess': {
         'type': {'type': string, 'default': 'huckel'},
         'file': {'type': str, 'default': ''},

pyoqp/oqp/library/runfunc.py

@@ -17,7 +17,7 @@
 NOT_AVAILABLE_RUNTYPES = {"soc", "neb"}
 ALL_RUNTYPES = SUPPORTED_RUNTYPES | NOT_AVAILABLE_RUNTYPES
 
-METHODS = {"hf", "tdhf", "dftb"}
+METHODS = {"hf", "tdhf"}
 SCF_TYPES = {"rhf", "rohf", "uhf"}
 TDHF_TYPES = {"rpa", "tda", "sf", "mrsf", "umrsf"}
 GUESS_TYPES = {"huckel", "hcore", "json", "auto", "pyscf", "sad", "sap"}
@@ -37,7 +37,7 @@
 
 WIKI_HELP = {
     "input.runtype": "Use energy, grad, hess, nac, nacme, optimize, meci, mecp, mep, ts, prop, or data. soc and neb are recognized but not implemented yet.",
-    "input.method": "Use method=hf for HF/DFT, method=tdhf for TDHF/TDDFT/SF/MRSF, or method=dftb for the optional external DFTB+ backend.",
+    "input.method": "Use method=hf for HF/DFT and method=tdhf for TDHF/TDDFT/SF/MRSF runs.",
     "input.system": "Set system to an XYZ file path or inline coordinates with one atom per indented line.",
     "input.basis": "Set basis to a basis name, a comma-separated per-atom list, or library with tagged atoms and [input] library mappings.",
     "scf.type": "RHF is for multiplicity 1 closed-shell references. SF/MRSF needs an open-shell reference, usually ROHF.",
@@ -251,9 +251,6 @@ def _check_system(config: dict[str, Any], report: CheckReport) -> None:
 
 
 def _check_basis(config: dict[str, Any], report: CheckReport) -> None:
-    if _as_lower(_get(config, "input", "method", "hf")) == "dftb":
-        return
-
     basis = _get(config, "input", "basis", "")
     system = _get(config, "input", "system", "")
     library = _get(config, "input", "library", "")
@@ -1179,22 +1176,10 @@ def check_input_values(
             "Unknown electronic structure method.",
             value=method,
             expected=", ".join(sorted(METHODS)),
-            action="Choose hf, tdhf, or dftb.",
+            action="Choose hf or tdhf.",
             wiki=WIKI_HELP["input.method"],
         )
 
-    runtype = _as_lower(_get(config, "input", "runtype", "energy"))
-    if method == "dftb" and runtype not in {"energy", "grad"}:
-        report.add(
-            "ERROR",
-            "input.runtype",
-            "DFTB+ backend currently supports runtype=energy or grad only.",
-            value=runtype,
-            expected="energy, grad",
-            action="Use runtype=energy or runtype=grad for method=dftb.",
-            wiki=WIKI_HELP["input.runtype"],
-        )
-
     _check_system(config, report)
     _check_basis(config, report)
     _check_guess(config, report)