7. Input File

When you use the command mast -i <inputfile>.inp, MAST does the following:

• Reads the input file
• Creates a recipe directory in $MAST_SCRATCH
• Creates the ingredient directories under that recipe directory
• Creates all the necessary metadata.txt files for that recipe and its ingredients.

MAST will then copy the input file into that recipe directory, as input.inp.

MAST will refer to this recipe-local input.inp file for all subsequent contact with the recipe.

7.1. General structure of the input file

The input file has many sections. Sections are denoted by $<section name> and $end:

$section

section_text
section_keyword keyword_value

$end

Within each section there may also be subsections, with keywords and values. Subsections are denoted by begin <subsection name> and end.:

$section

section_text
section_keyword keyword_value

begin subsection
subsection_text
subsection_keyword subsection_keyword_value
end

$end

• Comments in the input file are allowed only as separate lines, starting with the # sign.
• A comment may not be appended to a line.

7.2. Sections of the input file

See Sections of the Input File

7.3. Looping in the input file

If special looping tags are present in the input file, MAST can read in a single input file and create several permutated recipes in $MAST_SCRATCH.

The looping tag indeploop may be used to create combinatorial permutations.

• indeploop may be used once at the beginning of a line (that is not a section or subsection header or “end” line).
• indeploop may be used multiple times in an input file.

When indeploop is present at the beginning of the line, input file permutations will be created depending on the values in parentheses.

indeploop keyword1 (k1value1,k1value2)

The previous line would create two input files and corresponding recipes. On the line that used to have indeploop on it, one input file would have:

keyword1 k1value1

The other input file would have:

keyword1 l1value2

If indeploop tags are present multiple times in the recipe, input files are created combinatorially:

indeploop keyword1 (k1value1,k1value2)
indeploop keyword2 (k2value1,k2value2)

The previous two lines in an input file would create four input files and corresponding recipes. One input file would have:

keyword1 k1value1
keyword2 k2value1

Another would have:

keyword1 k1value1
keyword2 k2value2

A third would have:

keyword1 k1value2
kewyord2 k2value1

A fourth would have:

keyword1 k1value2
keyword2 k2value2

Sometimes, instead of combinatorial looping, some loops are meant to go together. In this case, the pegloop1 and pegloop2 tags may be used.

• There are only two pegged looping tags allowed, pegloop1 and pegloop2.
• Each tag may be used only once on a line.
• Each tag may be used on multiple lines.

Every line that starts with pegloop1 (the same will apply for pegloop2) will loop over keyword values, much like indeploop. However, the point of the pegged loops is to have two or more keywords loop together.

For example:

pegloop1 keyword1 (k1value1,k1value2)
pegloop1 keyword2 (k2value1,k2value2)

Using the pegloop1 tag, the lines above would not produce four input files and corresponding recipes, as they would when using the indeploop tag. Instead, they would produce only two input files and corresponding recipes.

One input file would have:

keyword1 k1value1
keyword2 k2value1

The other input file would have:

keyword1 k1value2
keyword2 k2value2

The number of items in parentheses should be equal for all instances of the pegloop1 (or, separately, the pegloop2) tag.

pegloop1, pegloop2, and all instances of indeploop will work combinatorially with each other.

Complex example (for looping only - many other necessary lines in the input file are skipped):

$mast
pegloop1 system_name (strain1,strain2,strain3)
$end

$structure
begin lattice
pegloop1 (3,4,5) 0 0
pegloop1 0 (3,4,5) 0
pegloop1 0 0 (3,4,5)
end

begin elementmap
pegloop2 X1 (Cr,Mn)
end
$end

$ingredients
begin ingredients_global
indeploop mast_xc (pw91,pbe)
LDAUJ 1
pegloop2 LDAUU (4.5,5)
end
$end

The above example would create 3*2*2 = 12 input files and corresponding recipes. The input file for the one of the recipes would look like:

$mast
system_name strain2
$end

$structure
begin lattice
4 0 0
0 4 0
0 0 4
end

begin elementmap
X1 Mn
end
$end

$ingredients
begin ingredients_global
indeploop mast_xc pbe
LDAUJ 1
LDAUU 5
end
$end