The Maxwell equations are in principle scale-invariant. However the program is intended to run in the atomic range. To be consistent use for:

light.theta

  type: decimal number
Desc: Theta angle of the incoming light in degrees

light.phi

 type: decimal number
 Desc: Phi angle of the incoming light in degrees
 

light.k

 type: Vec3 (only readable)
 Desc: The current wavevector of the incoming light
 

light.energy

type: decimal number
Desc: Energy of incoming light in eV

light.polarization (string)

type: string
valid values: 
	"S" : Sigma polarization (perpendicular to the scattering plane)
	"P" : Pi polarization (parallel to the scattering plane)
	"L" : Left circular polarization
	"R" : Right circular polarization
Desc: Defines the polarization of the incoming light dependent in relation to the HK=0,0 scattering plane. 

light.filter (string)

type: string
valid values: 
	"N" : none polarization filter (default)
	"S" : Sigma polarization filter (perpendicular to the scattering plane)
	"P" : Pi polarization filter (parallel to the scattering plane)
	"L" : Left circular polarization filter
	"R" : Right circular polarization filter
Desc: Defines the polarization filter of the outgoing light.

light.out TODO

BuildScatterMatrix()

 return value: nothing
 Desc: Calculates the scattering matrices for the whole layer structure. It depends on almost all parameters given earlier and executes the main routine.

atom.NewScatteringFactorAtom(number, number)

1. argument: real part of scattering factor (f1)
2. argument: imaginary part of scattering factor (f2)
return value: atom type
Desc: Generates a energy-independent atom type

atom.NewAtom(string)

1. argument: short element name like "Ti" for Titanium
return value: atom type
Desc: tries to find name.ff in order to load the scattering factor files or uses the internal database.

atom.NewAtom(string, q)

1. argument: short element name like "Ti" for Titanium
2. argument: defines the scattering for a certain momentum transfer q [Unit: A^-1]
return value: atom type
Desc: tries to find name.ff in order to load the scattering factor files or uses the internal database.

atom.NewMagneticAtom(number, number, number, number, number, number)

1. argument: real part of scattering factor (f1)
2. argument: imagninary part of scattering factor (f2)
3. argument: real part of magnetic scattering factor (f1m)
4. argument: imagninary part of magnetic scattering factor (f2m)
5. argument: direction of magnetiztion (theta angle in degrees)
6. argument: direction of magnetization (phi angle in degrees)
return value: atom type
Desc: Generates a energy-independent atom type with magnetic contributions

atom.NewScatteringFactorFileAtom(string)

1. argument: filename of tabulated scattering factors	
return value: atom type
Desc: Generates a energy-dependent atom type

atom.NewScatteringTensorFileAtom(string)

1. argument: filename of tabulated scattering tensors
return value: atom type
Desc: Generates a energy-dependent atom type

rl.Set(vec2, vec2, Decimal number, Decimal number)

 1. Argument: First unit cell vector in-plane
 2. Argument: Second unit cell vector in-plane
 3. Argument: unit cell length in z-direction. This is needed to define the l-value in the function SetThetaHKL
 Desc: Sets the lattice parameters in 2D. Adds the mandatory reciprocal lattice vector (H,K)=(0,0)
 return value: nothing

rl.b1() rl.b2() rl.b3()

 return value: Vec3
 Desc: Returns the three reciprocal lattice vectors.

rl.GetN()

 return value: integer
 Desc: return the number of reciprocal lattice vectors calculated.

rl.AddReciprocalLatticeVector(number, number)

 1. Argument: Miller indice H of the reciprocal lattice vector
 2. Argument: Miller indice K of the reciprocal lattice vector
 return value: nothing
 Desc: Adds a reciprocal lattice vector HK to the list of vector, which have to be calculated

rl.SetRadius(number)

 1. Argument: Radius in the reciprocal lattice space
 return value: nothing
 Desc: Renews the list of reciprocal lattice vectors with a list of all reciprocal lattice vector withing the radius
 

slabs.AddSlabs(number, number)

 1. Argument: number of slabs to create
 2. Argument: thickness of each slab
 return value: nothing

slabs.AddAtom(number, atom type, Vec3)

 1. Argument: add to the slab with index i
 2. Argument: the variable with the atom type
 3. Argument: Position of the atom inside the slab
 return value: nothing

slabs.SetStructure(string)

 Desc: Describes the final film structure. These are basically comma seperated slab indices or variables defined in slabs.DefineCrystal
       Additionally it allows to place brackets and repetitions
 Examples:  "0,1"
            "100*(0,1)"
            "100*(1,2), 0"
            "100*(0,1), 100000*(2)"
            "100*( 2*(0,1), 2*(3,4) )"
            "Crys1, Crys2" (if "Crys1" and "Crys2" were defined with slabs.CreateCrystal or the other functions)
 return value: nothing
 

slabs.CreateCrystal(string, string)

 1. argument: Variable name of this structure. Allowed signs: 'a'-'z', 'A'-'Z', '_', and '0'-'9' if it is not the first sign
 2. argument: Crystal definition like in the function slabs.SetStructure
 return value: nothing
 Desc: Defines a seperate crystal which can be used in the function slabs.SetStructure

slabs.CreateHom(string, string)

 1. argument: Variable name of this structure. Allowed signs: 'a'-'z', 'A'-'Z', '_', and '0'-'9' if it is not the first sign
 2. argument: Crystal definition like in the function slabs.SetStructure
 return value: nothing
 Desc: Defines a slab of an unordered crystal. The crystal is reduced to a continuum with the correct optical constants

slabs.CreateInterface(string, string, string, number, number)

 1. argument: Variable name of this structure. Allowed signs: 'a'-'z', 'A'-'Z', '_', and '0'-'9' if it is not the first sign
 2. argument: Crystal definition of the top crystal like in the function slabs.SetStructure
 3. argument: Crystal definition of the bottom crystal like in the function slabs.SetStructure
 4. argument: Total thickness of this interface with unordered crystal. The interface will be in the center of this slab.
 5. argument: Discretization of this interface. (around 3*thickness/sigma)
 6. argument: Roughness sigma in Angstrom
 return value: nothing
 Desc: Defines a slab with two unordered crystal and a rough interface. 

PrintStats()

 return value: nothing

GetRefl(number)

 return value: Decimal Number

GetTrans(number)

 return value: Decimal Number

GetReflK(number)

  return value: Vec3

GetTransK(number)

  return value: Vec3

SetThetaHKL(integer h, integer k, Decimal number l)

return value: integer (-1 if error)
Desc: Calculates the angle theta for a fixed phi angle and given hkl triple. Variable l can be non-integer. Returns the index of the reciprocal lattice vector.
	a negative number of l means transmission whereas a positive number means reflection. The calculated angle theta is automatically set in the variable light.theta

SetMultipleScattering(type)

return value: nothing
valid values: 
   MS.KINEMATIC:   Kinematical scattering (independent scatterers and independent light)
   MS.NONE:   No multiple scattering is calculated (enable light absorbtion and refraction)
   MS.LAYER:  Interlayer multiple scattering is enabled
   MS.INTERATOMIC: Interlayer as well as interatomic multiple scattering is enabled (not supported yet)

SetNumericAccuracy(type) (not supported yet)

valid values: 
   NUM.FLOAT: The decimals numbers are defined as 4 byte floating point numbers
   NUM.DOUBLE: The decimals numbers are defined as 8 byte floating point numbers
   NUM.LONGDOUBLE: The decimals numbers are defined as 10 byte floating point numbers. (Architecture dependent)
   NUM.QUAD: The decimals numbers are defined as 16 byte floating point numbers

SetMatrixAccuracy(type)

valid values:
   M.DIAGONAL: Neglect off-diagonal terms of the matrices. Very fast but leads to separate scattering channels.
   M.FULL: Use Full Matrix-Matrix-Multiplications
   M.BLAS: Like M.FULL but use of BLAS-libraries to increase performance of matrix-matrix-multiplication (not working yet)

queue.Add()

  Desc: Add current light configuration to queue

queue.Run()

  Desc: Execute the current queue parallelized

queue.Activate(integer)

  Variable1: Index in the queue beginning from zero
  Desc: Activates a result of the queue.

queue.GetN()

  return value: Number of entries in the queue

queue.Clear()

 Desc: Clears the queue (Bug: Memory is not freed)

fit.AddVariable(number, number, number, number)

1. argument: initial value for number
2. argument: stepsize of 1.arguement in first iteration . If unsure choose 0.1*initial_value. The value must not be zero!
3. argument: lower boundary for variable
4. argument: upper boundary for variable

fit.SetErrorFunction(function)

1. argument: Lua function which should return an error
Desc: The function receives a list of parameters (array of numbers), and should return an error (number)

fit.Iterate(number)

1. argument: Number of simplex iterations to perform

The tool convertcrystal converts crystal files in the format .xyz to an output that is usable for QUAD. The standard .cif can be usually exported to a .xyz file by using software tools like “Diamond” or “Vesta”. convertcrystal executes a script file which can contain following commands line by line. A example should be provided in the Tutorials folder

openxyz filename

opens a .xyz file

savexyz filename

saves a .xyz file

unitcell a b c anglea anbleb anglec

defines the unit cell structure of the loaded file. The definition can be found here: http://en.wikipedia.org/wiki/Fractional_coordinates

findneighbors

just prints the atom and tells how many other atoms at the same crystal position could be found

atomdistance d

Sets the distance limit in which the atoms are treated identical. (default 0.1A)

reduce

removes atoms that are multiple times in the crystal lattice (e. g. atoms at the corners) the function “removeoutside” should be executed first.

expand min max

expands the unit cell around the borders

sort

sort the atoms for increasing z-coordinate

rotatex angle

rotates crystal around x-axis

rotatey angle

rotates crystal around y-axis

rotatez angle

rotates crystal around z-axis

moveatom atomnr x y z

moves an atom around if atomnr is -1 then the whole crystal is moved

findcubiccell

trys to find the smallest cubic unitcell of the system. and sets the unit cell accordingly. If this function does not work you have to do it manually by the “unitcell” command.

buildlayers nlayers

prints the atom layers which you can use directly use in the lua script. Note that the layer will be build up along z-axis and not around c-axis.

pause

waits for a keypress (enter)

check

checks if there is something outside of the primitive outside of the unit cell and warns In future there will be more checks included

removeoutside

remove all atoms outside of the unit cell

printunitcellvectors

prints the current unit cell vectors a,b and c