Dear the developers of dftd4, I thank you very much for your contributions!

Describe the bug

For a 700 atom system with a periodic boundary condition, dftd4's gradient evaluation gives segmentation fault. We want to get the contribution of vdW correction and add it to existing vasp calculations.

Interestingly, the calculation ended well for a 200 atom system, and for the same 700 atom system without gradient evaluation, so it might be related to large system size for the gradient evaluation.

Also, when we ran vasp and called dftd4 inside vasp, which was compiled by a server manager, the calculation was okay. But we do not want to do the time-consuming vasp calculations for many structures. So we would like to obtain the contribution of vdW only from dftd4.

dftd4 was installed using conda, and used by itself or called by python interface, or compiled using cmake and gfortran, or using cmake and intel fortran compiler. In all cases there was segmentation fault.

To Reproduce
Steps to reproduce the behaviour:

1. happens with input (include input files):
   The input file is this: POSCAR.zip

2. start dftd4 with (all the options here):
   dftd4 -g -f r2SCAN POSCAR

3. output showing the error

                    ____  _____ _____     ____  _  _
      -------------|  _ \|  ___|_   _|---|  _ \| || |------------
     |             | | | | |_    | | ___ | | | | || |_           |
     |             | |_| |  _|   | ||___|| |_| |__   _|          |
     |             |____/|_|     |_|     |____/   |_|            |
     |             ===================================           |
     |            E. Caldeweyher, S. Ehlert & S. Grimme          |
     |          Mulliken Center for Theoretical Chemistry        |
     |                    University of Bonn                     |
      -----------------------------------------------------------

Rational (Becke-Johnson) damping: r2SCAN-D4-ATM
---------------------
  s6         1.0000
  s8         0.6019
  s9         1.0000
  a1         0.5156
  a2         5.7734
 alp        16.0000
--------------------

Segmentation fault (core dumped)

We thank you very much in advance!