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Showing posts from April, 2014

Buoyancy and the Archimedes' Principle

XRD: Structure Factor

Calculation of XRD pattern of h-LuFeO3 using python

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Updated on April 4, 2014 The calculation is divided into three parts: a) Get the atomic position of Lu, Fe and O from the given Wyckoff positions in a CIF file of h-LFO, b) Calculate the allowed (h, k, l) .  c) Find the atomic form factors of Lu, Fe and O for different (h, k, l) and use them to calculate structure factors. In the next step I calculate allowed hkl values. The condition imposed here is that the sine of Bragg angle for a k -vector should not exceed 1. This condition does not account for systematic absences . Peaks corresponding to systematic absences have 0 or negligible intensity in final calculations. The basis vectors in k -space were calculated manually. I plan to write a program to evaluate basis vectors in k -space. Next, I calculate the atomic form factors of Lu, Fe and O. Atomic form factors are functions of hkl and also depend on oxidation states of elements in the compound under study. The data on atomic form factors of vario