[RMCProfile-users] about using RMCProfile to simulate PDFgetX3 S(Q) and G(r)

姚伟鑫 yaoweixin at sjtu.edu.cn
Fri Oct 27 06:56:07 BST 2017

Dear Wojciech Slawinski, Martin Dove and other RMCProfile list members,

Thank you so much for your answering. According to your answering, the PDFgetX3 S(Q)-1 i.e. PDFgetX3 F(Q)/Q is supported by RMCProfile. Then I use the stog_new program in RMCProfile(version6.7.0) to get the G(r), setting the PDFgetX3 S(Q), which tends to be 1 at high Q, as the 's' of stog_new program. Is this stog G(r) correct for RMCProfile? 

By my reckoning, if I understand correctly, the (sum cibi)^2 =(sum ciZi)^2 for X-ray data, where Z is the atomic number. Thus (sum ciZi)^2 is the sum of the partial Faber-Ziman coefficients and should be 1. Therefore the PDFgetX3 G(r)=RMCProfile D(r)/(sum cibi)^2 =RMCProfile D(r)/(sum ciZi)^2=RMCProfile D(r)/1=RMCProfile D(r). If it is correct, then the PDFgetX3 G(r) can be fitted as D(r) in RMCProfile. Am I right?

Actually I have tried the stog_new program, setting the PDFgetX3 S(Q) as 's', the sum of the partial Faber-Ziman coefficients as 1 and got the RMCProfile_G(r). Then I find that the PDFgetX3 G(r) is equivalent to 4*pi*r*N*RMCProfile_G(r), where N is my sample's number density. I believe that confirms that the PDFgetX3 G(r)=RMCProfile D(r).

Hope to be corrected by you.

Yours sincerely,
Weixin Yao

More information about the rmcprofile-users mailing list