SET_ALTERNATE_CONDITION

This command is for the ED-EXP module.

A special command used in the experimental data *.POP file but also possible in the ED_EXP module. It is used only when you have specified that the alternate mode is set in the PARROT module.

In the DICTRA module, you work with a .DOP file instead of a .POP file.

The command syntax is almost the same as for the POLY command SET_CONDITION while the uncertainty should also be specified.

The alternate condition (including the normally POLY module condition plus uncertainly; see below) must be given explicitly, but can be given on the same line or on separate lines with each one started with the command.

Options	Description and Information
Syntax	set_alternate_condition
Prompt	State variable expression: <State variable name or linear expression> Give either a state variable or a linear expression of state variables.
State variables	Some of the state variables that can be used in conditions are: `T`: temperature in the system (in K) `P`: pressure in the system (in Pascal) `N`: system size (mole number in moles) `B`: system size (mass in grams) `N(<component>)`: mole number of a component in the system `X(<component>)`: mole fraction of a component in the system `W(<component>)`: weight fraction of a component in the system For the SET_CONDITION command this is `ACR(<component>)`: activity of a component in the system. For the SET-ALTERNATIVE_CONDITION command, this is `ACR`(<`phase`>,<`component`>) (activity of a component in a phase) For the SET_CONDITION command this is `MUR(<component>)`: chemical potential of a component in the system. For the SET-ALTERNATIVE_CONDITION command, this is `MUR`(<`phase`>,<`component`>) (chemical potential of a component in a phase) `X(<phase>,<component>)`: mole fraction of a component in a phase `W(<phase>,<component>)`: weight fraction of a component in a phase `ACR(<species>,<phase>)`: activity of a species referred to a phase `MUR(<species>,<phase>)`: chemical potential of a species referred to a phase `H`: enthalpy in the system (in J) `HM(<phase>)`: enthalpy of a phase (in J/mol)
Additional prompts	Factor: <A factor for the state variable, or a continuation> This question means that the previous question was not answered. The program is then expecting a single state variable or a complete state variable expression, or the numeric factor in an expression with only one state variable. In a state variable expression a state variable may be preceded by a constant factor. An example of this is: 2MUR(FE)+3MUR(O)=-35000 This means that it should be a condition that two times the chemical potential of FE plus three times the chemical potential of O should be -35000 J/mol.
	State variable: <A specified state variable, or a continuation> This question is prompted if a single state variable name has not given in either the prompt `State variable expression` or `Factor`, or a state variable expression is given but the expression is incomplete, for example, `T-` or `2*MUR(FE)+`, for which the program is then expecting a continuation of the unfinished expression. You need to specify a state variable or a complete state variable expression, or complete the unfinished state variable expression. If a numeric factor is given before this prompt, only one state variable can be specified; otherwise, the program only takes the first state variable to complete the expression (i.e. the factor times the state variable).
	Value /X/: <A numeric value, a constant or a variable> The value of the condition. This can be a numeric value, a constant or a variable. A suggestion is given as the default value. The special value `NONE` means that the condition is removed.
	Uncertainty /None/: <Uncertainty of the condition> The uncertainty of the condition. This can be a numeric value, a constant or a variable. The default value `NONE` means that the uncertainty for the value specified above is zero. The uncertainty can either be expressed as an absolute value or relative to the value of the condition in percent (`x%`).
Notes	There are more state variables that can be used in conditions. For more information, type an INFO STATE_VARIABLES command in the POLY module. A condition is normally a value of a single state variable with its value. Example T=1273.15 P=1E5 X(C)=.002 W(CR)=1.5 ACR(CR)=0.85 X(FCC,C)=.001 H=-250000 HM(BCC)=-225000 A condition can also be a value of a linear expression involving more than one state variable. Example X(LIQ,S)-X(PYRR,S)=0 This means that it is a condition that the mole fraction of `S` should be the same in the LIQUID and PYRRHOTITE phases. In practice that should be the congruent melting point. After the equal sign only a numeric value is allowed.