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m [2009/08/06 14:39] – created clarem [2024/02/22 16:32] (current) – created - external edit 127.0.0.1
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 +====== m ======
 +
 +**[//marquardt_constant// !E]…**
 +
 +Allows for changing the Marquardt constants, the Simulated_Annealing_1 macro changes the Marquardt constants as follows:
 +
 +load marquardt_constant { 0 1 }
 +
 +**[//min_r// #] [//max_r// #]**
 +
 +Defines the minimum and maximum radii for calculating bond lengths. //min_r// and //max_r// are by default set to 0 and 3.2 Å respectively.
 +
 +**[//mixture_density_g_on_cm3// !E]**
 +
 +Calculates the density of the mixture assuming a packing density of 1, see also //[[#k038|mixture_MAC]]////.//
 +
 +**[//mixture_MAC// !E]**
 +
 +Calculates the mass absorption coefficient in cm<sup>2</sup>/g for a mixture as follows:
 +
 +<sub>{{techref_files:image160.gif?160x45}}</sub>where //w//<sub>i</sub> and (//m/////r//)<sub>i</sub> is the weight percent and //phase_MAC// of phase i respectively. Errors are reported for //phase_MAC// and //mixture_MAC//.
 +
 +The following example provides phase and mixture mass absorption coefficients.
 +
 +xdd...
 +
 +mixture_MAC 0
 +
 +str...
 +
 +phase_MAC 0
 +
 +The macros Mixture_LAC_1_on_cm, Phase_LAC_1_on_cm and Phase_Density_g_on_cm3 calculates the mixture and phase linear absorption coefficients (for a packing density of 1) and phase density, for example:
 +
 +xdd...
 +
 +Mixture_LAC_1_on_cm(0)
 +
 +str...
 +
 +Phase_Density_g_on_cm3(0)
 +
 +Phase_LAC_1_on_cm(0)
 +
 +Errors for these quantities are also calculated. Mass absorption coefficients obtained from NIST at [[http://physics.nist.gov/PhysRefData/XrayMassCoef|http://physics.nist.gov/]][[http://physics.nist.gov/PhysRefData/XrayMassCoef|P]][[http://physics.nist.gov/PhysRefData/XrayMassCoef|hysRefData/XrayMassCoef]] are used to calculate //mixture_MAC// and //phase_MAC//.