63 INTEGER,
INTENT(IN) :: perd(3)
65 INTEGER :: i, j, k, shell
71 DO i = -shell*perd(1), shell*perd(1)
72 DO j = -shell*perd(2), shell*perd(2)
73 inner:
DO k = -shell*perd(3), shell*perd(3)
74 IF (.NOT. (i**2 + j**2 + k**2 == shell)) cycle inner
79 IF (all(m .EQ. (/i, j, k/))) found = .true.