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### ecoord command

**Syntax:**

ecoord N eng

- N = coordination number (see asterisk form below)
- eng = energy of site with this coordination number (energy units)

**Examples:**

ecoord 8 5.6
ecoord 0 1.0e20
ecoord * 1.0
ecoord 8*12 10.0

**Description:**

This command sets the energy of an occupied site in a lattice as a
function of coordination number, where coordination = the number of
occupied neighbor sites. See the app_style diffusion
nonlinear command for how the energy change of the
system due to a diffusive hop is used to calculate a probability for
the hop to occur.

Typically, Nmax+1 values should be specified by using this command one
or more times, with N varying from 0 to Nmax, when Nmax is the number
of neighbor sites for each lattice site.

The N index can be specified in one of two ways. An explicit numeric
value can be used, as in the 1st example above. Or a wild-card
asterisk can be used to set the energy value for multiple coordination
numbers. This takes the form "*" or "*n" or "n*" or "m*n". If Nmax =
the number of neighbor sites, then an asterisk with no numeric values
means all coordination numbers from 0 to Nmax. A leading asterisk
means all coordination numbers from 0 to n (inclusive). A trailing
asterisk means all coordination numbers from n to Nmax (inclusive). A
middle asterisk means all coordination numbers from m to n (inclusive).

Note that if the third example is specfied first, followed by the
first example, then the effect would be to set the energy value for
all coordination numbers to 1.0, then overwrite the energy value for
coordination number 8 to 5.6.

The *eng* value should be in the energy units defined by the
application's Hamiltonian and should be consistent with the units used
in any temperature command.

**Restrictions:**

This command can only be used as part of the app_style diffusion
nonlinear application.

**Related commands:**

deposition, barrier

**Default:**

Energy values for all coordination numbers are set to 0.