Error Propagation for Bond Distances

CrystalMaker will calculate error values for bond distances, if you have provided error values for the unit cell parameters and/or the fractional coordinates for atoms in the asymmetric unit.

The best way to get error information into CrystalMaker is to read in a CrystalMaker text file that contains the error values (see Appendix B: CrystalMaker Text Format in the CrystalMaker User's Guide). You will need to have an ERRS card followed by the errors in the structural data, and also an ERRC card, followed by the errors in the cell parameters. Here is a crude example:-


				TITL  Test file!											

				NOTE														

				This is a test to demonstrate error propagation...			

																			

				CELL     10	10	10	90	90	90								

				!															

				! NOTE the "ERRC" card: errors in the unit					

				! cell parameters; I've guessed these errors -				

				! they're probably bigger than the true errors!				

				!															

				ERRC	  1.0	0.0	0.0	0.0	0.0	0.0							

				!															

				SPGR  P 1              										

				XYZR    0.9000  2.1000  0.9000  2.1000  0.9000  2.1000		

				MODL  1														

				BKCL     0.58061   0.65992   1.00000						

				SHCL  1														

				COLS  1														

				TYPE														

				Si    0.40    0.6043  0.6043  1.0000						

				O     1.21    1.0000  0.0000  0.0000						

				ATOM														

				Si  T1          0	0	0									

				O	Oz			0.5	0.0	0.0									

				!															

				! Note the new "errors" line: The syntax is: 				

				! {site label} {sigma x} {Sigma y} {sigma z}				

				!                                                           

				ERRS														

				T1	0.1	0.1	0.1												

				Oz	0.0	0.0	0.0

You can then read the text file into CrystalMaker, using the File > Open command.

Error bars for bond distances