feature: TDDFT-ris (pyscf#367)

* TDDFT-ris with cupy speedup &  nonorthonormal Krylov space methods

* feat: implement RIS enhancements with file updates and tests

* ris: syntax and test tolerance

* einsum Ppq Cup Cvq now uses cupy_helper.contract; cp.zeros / cp.zeros_like -> cp.empty / cp.empty_like ; parameter docs ; remove prints ;

* typo and logwarn

* log timer; ris build; cholesky; magic number; eisum-> contract; TODO:test large systems

* HARTREE2WAVENUMBER & bare except

* Update GS flag in _lr_eig.py

* example number

---------

Co-authored-by: zhouzehao.dbsv <[email protected]>
Co-authored-by: Qiming Sun <[email protected]>
Co-authored-by: Xiaojie Wu <[email protected]>

Author: 4 people

examples/32-tddft_ris.py

@@ -0,0 +1,68 @@
+# Copyright 2021-2025 The PySCF Developers. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+# Example of TDDFT-ris
+
+
+import pyscf
+from gpu4pyscf.dft import rks
+import gpu4pyscf.tdscf.ris as ris
+
+atom ='''
+C         -4.89126        3.29770        0.00029
+H         -5.28213        3.05494       -1.01161
+O         -3.49307        3.28429       -0.00328
+H         -5.28213        2.58374        0.75736
+H         -5.23998        4.31540        0.27138
+H         -3.22959        2.35981       -0.24953
+'''
+
+mol = pyscf.M(atom=atom, basis='def2-svp', verbose=4)
+mf = rks.RKS(mol, xc='wb97x').density_fit()
+
+e_dft = mf.kernel()
+print(f"total energy = {e_dft}")
+
+
+
+''' TDDFT-ris'''
+td = ris.TDDFT(mf=mf.to_gpu(), nstates=10, spectra=True)
+td.kernel()
+# energies, X, Y, oscillator_strength, rotatory_strength = td.kernel()
+
+energies = td.energies
+# X = td.X
+# Y = td.Y
+oscillator_strength = td.oscillator_strength
+rotatory_strength = td.rotatory_strength
+
+print("TDDFT-ris ex energies", energies)
+print("TDDFT-ris oscillator_strength", oscillator_strength)
+
+''' TDA-ris'''
+td = ris.TDA(mf=mf.to_gpu(), nstates=10)
+td.kernel()
+# energies, X, oscillator_strength, rotatory_strength = td.kernel()
+
+energies = td.energies
+# X = td.X
+oscillator_strength = td.oscillator_strength
+rotatory_strength = td.rotatory_strength
+
+print("TDA-ris ex energies", energies)
+print("TDA-ris oscillator_strength", oscillator_strength)
+
+
+

gpu4pyscf/lib/logger.py

@@ -59,6 +59,20 @@ def timer(rec, msg, cpu0=None, wall0=None, gpu0=None):
             flush(rec, '    CPU time for %s %9.2f sec' % (msg, t0-cpu0))
         return t0,
 
+def timer_silent(rec, cpu0=None, wall0=None, gpu0=None):
+    if gpu0:
+        t0, w0, e0 = process_clock(), perf_counter(), cupy.cuda.Event()
+        e0.record()
+        e0.synchronize()
+        return t0-cpu0, w0-wall0, cupy.cuda.get_elapsed_time(gpu0,e0)
+    elif wall0:
+        t0, w0 = process_clock(), perf_counter()
+        return t0-cpu0, w0-wall0
+    else:
+        t0 = process_clock()
+        return t0-cpu0,
+
+
 def _timer_debug1(rec, msg, cpu0=None, wall0=None, gpu0=None, sync=True):
     if rec.verbose >= DEBUG1:
         return timer(rec, msg, cpu0, wall0, gpu0)
@@ -103,6 +117,7 @@ def __init__(self, stdout=sys.stdout, verbose=NOTE):
     timer_debug2 = _timer_debug2
     timer = timer
     init_timer = init_timer
+    timer_silent = timer_silent
 
 def new_logger(rec=None, verbose=None):
     '''Create and return a :class:`Logger` object