Files
sics/difrac/params.f
2000-02-07 10:38:55 +00:00

22 lines
689 B
Fortran

C-----------------------------------------------------------------------
C To extract real or reciprocal cell parameters from the metric
C tensor G into ABC and ANG
C-----------------------------------------------------------------------
SUBROUTINE PARAMS (G,ABC,ANG)
DIMENSION G(3,3),ABC(3),ANG(3)
DEG = 57.2958
DO 100 I = 1,3
ABC(I) = SQRT(G(I,I))
100 CONTINUE
P = G(2,3)/(ABC(2)*ABC(3))
Q = SQRT(1.0 - P*P)
ANG(1) = DEG*ATAN2(Q,P)
P = G(1,3)/(ABC(1)*ABC(3))
Q = SQRT(1.0 - P*P)
ANG(2) = DEG*ATAN2(Q,P)
P = G(1,2)/(ABC(1)*ABC(2))
Q = SQRT(1.0 - P*P)
ANG(3) = DEG*ATAN2(Q,P)
RETURN
END