diff options
author | Thomas White <taw@physics.org> | 2009-11-17 15:43:05 +0100 |
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committer | Thomas White <taw@physics.org> | 2009-11-17 15:43:05 +0100 |
commit | 50ffbc353574996546e51a61ec4566f461769fc3 (patch) | |
tree | e5df514215814f4f6b1e0f92195b9e209e35fe90 /src/diffraction.c | |
parent | 04c4c604f03d7c9729684b7b226a9ef695ece21d (diff) |
Move scattering factor stuff to new file
Diffstat (limited to 'src/diffraction.c')
-rw-r--r-- | src/diffraction.c | 142 |
1 files changed, 1 insertions, 141 deletions
diff --git a/src/diffraction.c b/src/diffraction.c index e02d80f4..b5c07a71 100644 --- a/src/diffraction.c +++ b/src/diffraction.c @@ -21,6 +21,7 @@ #include "cell.h" #include "ewald.h" #include "diffraction.h" +#include "sfac.h" static double lattice_factor(struct threevec q, double ax, double ay, double az, @@ -59,147 +60,6 @@ static double lattice_factor(struct threevec q, double ax, double ay, double az, } -/* Look up f1 and f2 for this atom at this energy (in J/photon) */ -static double complex get_f1f2(const char *n, double en) -{ - FILE *fh; - char filename[64]; - char line[1024]; - char *rval; - float last_E, last_f1, last_f2; - - snprintf(filename, 63, "scattering-factors/%s.nff", n); - fh = fopen(filename, "r"); - if ( fh == NULL ) { - fprintf(stderr, "Couldn't open file '%s'\n", filename); - return 0.0; - } - - en = J_to_eV(en); - - /* Discard first line */ - fgets(line, 1023, fh); - - last_E = 0.0; - last_f1 = 0.0; - last_f2 = 0.0; - do { - - int r; - float E, f1, f2; - - rval = fgets(line, 1023, fh); - - r = sscanf(line, "%f %f %f", &E, &f1, &f2); - if ( r != 3 ) { - fprintf(stderr, "WTF?\n"); - abort(); - } - - /* Find the first energy greater than the required value */ - if ( E < en ) { - /* Store old values ready for interpolation*/ - last_E = E; - last_f1 = f1; - last_f2 = f2; - } else { - - /* Perform (linear) interpolation */ - float f; - float actual_f1, actual_f2; - - f = (en - last_E) / (E - last_E); - - actual_f1 = last_f1 + f * (f1 - last_f1); - actual_f2 = last_f2 + f * (f2 - last_f2); - - fclose(fh); - return actual_f1 + I*actual_f2; - - } - - } while ( rval != NULL ); - - fclose(fh); - - fprintf(stderr, "Couldn't find scattering factors for '%s' at %f eV!\n", - n, en); - - return 0.0; -} - - -/* s = sin(theta)/lambda */ -static double get_waas_kirf(const char *n, double s) -{ - FILE *fh; - char *rval; - double f; - float a1, a2, a3, a4, a5, c, b1, b2, b3, b4, b5; - double s2; - - fh = fopen("scattering-factors/f0_WaasKirf.dat", "r"); - if ( fh == NULL ) { - fprintf(stderr, "Couldn't open f0_WaasKirf.dat\n"); - return 0.0; - } - - do { - - int r; - char line[1024]; - char sp[1024]; - int Z; - - rval = fgets(line, 1023, fh); - - if ( (line[0] != '#') || (line[1] != 'S') ) continue; - - r = sscanf(line, "#S %i %s", &Z, sp); - if ( (r != 2) || (strcmp(sp, n) != 0) ) continue; - - /* Skip two lines */ - fgets(line, 1023, fh); - fgets(line, 1023, fh); - - /* Read scattering coefficients */ - rval = fgets(line, 1023, fh); - r = sscanf(line, " %f %f %f %f %f %f %f %f %f %f %f", - &a1, &a2, &a3, &a4, &a5, &c, &b1, &b2, &b3, &b4, &b5); - if ( r != 11 ) { - fprintf(stderr, "Couldn't read scattering factors\n"); - return 0.0; - } - - break; - - } while ( rval != NULL ); - - fclose(fh); - - s2 = pow(s/1e10, 2.0); /* s2 is s squared in Angstroms squared */ - f = c + a1*exp(-b1*s2) + a2*exp(-b2*s2) + a3*exp(-b3*s2) - + a4*exp(-b4*s2) + a5*exp(-b5*s2); - - return f; -} - - -/* Get complex scattering factors for element 'n' at energy 'en' (J/photon), - * at resolution 's' = sin(theta)/lambda (in m^-1) */ -static double complex get_sfac(const char *n, double s, double en) -{ - double complex f1f2; - double fq, fq0; - - f1f2 = get_f1f2(n, en); - fq = get_waas_kirf(n, s); - fq0 = get_waas_kirf(n, 0.0); - - return fq - fq0 + f1f2; -} - - /* Return structure factor for molecule 'mol' at energy en' (J/photon) at * scattering vector 'q' */ static double complex molecule_factor(struct molecule *mol, struct threevec q, |