(1) rigid shift of the molecule along x, 8 steps across one grid spacing of the 500 Ry grid
                                              grid    E p-p  net force   -dE/dx  ratio    on F
                                                      (meV)    (meV/A)  (meV/A)        (meV/A)
    r2SCAN  XC_DERIV PW (default)   500 Ry     180     6.29       1312      291   4.50    1292
    r2SCAN  XC_DERIV SPLINE3        500 Ry     180     5.11        237      237   1.00     211
    rSCAN   XC_DERIV PW (default)   500 Ry     180    10.17        451      449   1.00     486
    r2SCAN  XC_DERIV PW (default)  1500 Ry     300     0.23         15       15   0.98      19
    r2SCAN  PW, patched libxc       500 Ry     180     6.37        298      295   1.01     273

(2) CP2K RUN_TYPE DEBUG at shift 2 (F a quarter of a grid spacing from a grid point), forces in meV/A
                                            component      numerical analytical difference
    r2SCAN  XC_DERIV PW (default)   500 Ry  F x                 -256      -1178     -921.8
                                            F y                  467        470        2.4
                                            F z                 -129        -41       88.7
                                            sum over atoms x    -323      -1236     -913.0
    r2SCAN  XC_DERIV SPLINE3        500 Ry  F x                 -200       -200       -0.2
                                            F y                  466        466        0.0
                                            F z                 -140       -140        0.0
                                            sum over atoms x    -269       -269       -0.2
    rSCAN   XC_DERIV PW (default)   500 Ry  F x                 -427       -427       -0.3
                                            F y                  460        460       -0.0
                                            F z                  -25        -25        0.1
                                            sum over atoms x    -438       -438       -0.3
    r2SCAN  XC_DERIV PW (default)  1500 Ry  F x                   28         28       -0.1
                                            F y                  463        463       -0.0
                                            F z                 -146       -146        0.0
                                            sum over atoms x      -5         -5       -0.0
