Create formulation based on concentrations

Description

This function can be used to create formulations targeting a specific density and that contain several molecules at a given concentration. This function can have an unlimited number of parents.
A concentration (in weight percentage, % w/w) must be associated with every parent through the corresponding input.
Starting from the concentrations, the definition of a simulation cell and a target density, the number of copies of parent molecules to insert in the system is calculated.
The order of insertion in the system is controlled by the input Insertion ordering. Except for specific cases, it is recommended to insert the heaviest molecules first.
The other inputs, which control some features of the insertion procedure, are the same as those of the create and fill cell function.

Latest version

Allowed number of parents: from 2 to N

  1. Any system that wants to be inserted. A concentration will be associated to each one of them

Parameter Description Value type Value restrictions Default value Units

Cell dimensions

The three cell lengths (x,y,z)

float

>0

[0.0, 0.0, 0.0]

Angstrom

Target concentration for component i

One for every parent, defines the concentration of that parent in the final formulation.

int

>0

0

% w/w

Insertion ordering

The ordering of insertion of the copies of the parent molecules

selector

according to hierarchy of parents, random, according to molecular weight of parents (heaviest first)

according to molecular weight of parents (heaviest first)

N/A

Density of the formulation

The target density of the formulation. Together with the concentrations indicated for each component and the cell volume, determines the actual number of molecules that will be inserted

float

>0

0

g/cm3

Orientation

The orientation of the components to be inserted

selector

random, regular

random

N/A

Position

The position within the cell where the components shall be inserted

selector

random, spacefilling

random

N/A

Minimal distance between atoms

Minimal distance between two inserted components.

float

>0

2.0

Angstrom

Periodic boundary conditions

Indicates whether we have periodic boundary conditions in x, y and z

boolean

True, False

[True, True,True]

N/A

Seed for random generation

The seed used in the random generator, -1 can be selected for a random seed

int

>-1

123

N/A

Enable minimization

Indicates if a GROMACS energy minimization should be performed to increase the insertion success rate

boolean

True, False

False

N/A