Water fixes

2 files changed, 13 insertions, 8 deletions

diff --git a/src/detector.c b/src/detector.c
index 2d095611..a0b09799 100644
--- a/src/detector.c
+++ b/src/detector.c
@@ -157,20 +157,25 @@ void record_image(struct image *image)
 	for ( x=0; x<image->width; x++ ) {
 	for ( y=0; y<image->height; y++ ) {
 
-		double counts,  intensity, sa;
+		double counts, intensity, sa, water;
 		double complex val;
 
 		val = image->sfacs[x + image->width*y];
 		intensity = (double)(val * conj(val));
 
 		/* Add intensity contribution from water */
-		intensity += water_intensity(image->qvecs[x + image->width*y],
-		                            image->xray_energy);
+		water = water_intensity(image->qvecs[x + image->width*y],
+		                        image->xray_energy);
+
+		//printf("%e + %e", intensity, water);
+		intensity += water;
+		//printf(" = %e\n", intensity);
 
 		/* What solid angle is subtended by this pixel? */
 		sa = sa_per_pixel * cos(image->twotheta[x + image->width*y]);
 
 		counts = intensity * ph_per_e * sa;
+		//printf("%e counts\n", counts);
 
 		image->hdr[x + image->width*y] = counts;
 
diff --git a/src/diffraction.c b/src/diffraction.c
index 6351042d..8cf3f4ed 100644
--- a/src/diffraction.c
+++ b/src/diffraction.c
@@ -103,7 +103,7 @@ double water_intensity(struct threevec q, double en)
 {
 	double complex fH, fO;
 	double s, modq;
-	double intensity;
+	double complex ifac;
 
 	/* Interatomic distances in water molecule */
 	const double rOH = 0.09584e-9;
@@ -128,15 +128,15 @@ double water_intensity(struct threevec q, double en)
 	fO = get_sfac("O", s, en);
 
 	/* Four O-H cross terms */
-	intensity = 4.0*fH*fO * sin(modq*rOH)/(modq*rOH);
+	ifac = 4.0*fH*fO * sin(2.0*M_PI*modq*rOH)/(2.0*M_PI*modq*rOH);
 
 	/* Three H-H cross terms */
-	intensity += 3.0*fH*fH * sin(modq*rHH)/(modq*rHH);
+	ifac += 3.0*fH*fH * sin(2.0*M_PI*modq*rHH)/(2.0*M_PI*modq*rHH);
 
 	/* Three diagonal terms */
-	intensity += 2.0*fH*fH + fO*fO;
+	ifac += 2.0*fH*fH + fO*fO;
 
-	return intensity * n_water;
+	return cabs(ifac) * n_water;
 }