A user has requested the ability to perform a powder simulation for a sample with preferred orientation of crystallites, using the formulism used in powder crystallography, specifically the March formula (article in German - see also this article) as implemented in FullProf which posits a distribution of preferred Q vectors defined by an angle alpha between Q and a preferred orientation direction n (called PREF by FullProf) as:
Where the March parameter r (called G1 by FullProf) in the range [-1,1] determines the habit of the preferred orientation, and the parameter f (called G2 by FullProf) is the fraction of sample which has normal (random) orientations.
It would be nice if in powspec we can implement a preferred orientation mechanism where the user can input the preferred direction n, the r and f parameters and we can then sample on the sphere surface according to the March formula.
A user has requested the ability to perform a powder simulation for a sample with preferred orientation of crystallites, using the formulism used in powder crystallography, specifically the March formula (article in German - see also this article) as implemented in FullProf which posits a distribution of preferred Q vectors defined by an angle
alphabetween Q and a preferred orientation direction n (calledPREFby FullProf) as:Where the March parameter r (called
G1by FullProf) in the range [-1,1] determines the habit of the preferred orientation, and the parameter f (calledG2by FullProf) is the fraction of sample which has normal (random) orientations.It would be nice if in
powspecwe can implement a preferred orientation mechanism where the user can input the preferred direction n, the r and f parameters and we can then sample on the sphere surface according to the March formula.