2. Templates

Bfrescox works by using templates to generate input files for Frescox runs. The Bfrescox configuration interface includes functionality for creating templates and final Frescox input files for common scattering simulations such as elastic and inelastic scattering. Such templates can be generated automatically. Bfrescox also allows users to create their own templates, and, whether the template was generated automatically or created by the user, Bfrescox fills them in and runs Frescox with them the same way.

The way templates work is simple: take any existing Frescox input file, and replace any values you want with keys of the following format: “@key_name@”. The set of such replacements constitutes the set of parameters one can vary. For example, consider the following simple Frescox input file:

p+Ni78 Coulomb + Nuclear
NAMELIST
&FRESCO hcm=0.1 rmatch=60.0
    jtmin=0.0 jtmax=60.0 absend= 0.01
  thmin=0.00 thmax=180.00 thinc=1.00
    iter=0 ips=0.0 iblock=0 chans=1 smats=2  xstabl=1
  wdisk=2
    elab(1)=50.0 treneg=1 /

 &PARTITION namep='projectile' massp=1 zp=1
            namet='target'   masst=78 zt=28 qval=-0.000 nex=1  /
 &STATES jp=0.5 bandp=1 ep=0.0000 cpot=1 jt=0.0 bandt=1 et=0.0 /
 &partition /

 &POT kp=1 ap=1 at=78 rc=1.2  /
 &POT kp=1 type=1  p1=@V@ p2=@r@ p3=@a@ p4=@W@ p5=@rw@ p6=@aw@ /
 &POT kp=1 type=2  p1=@Vs@ p2=@rs@ p3=@as@ p4=@Ws@ p5=@rws@ p6=@aws@ /
 &POT kp=1 type=3  p1=@Vso@ p2=@rso@ p3=@aso@ p4=@Wso@ p5=@rwso@ p6=@awso@ /

 &pot /
 &overlap /
 &coupling /

This template file is identical to a normal Frescox input file, except that the parameters of the optical potential have been replaced with keys of the form “@key_name@”. When Bfrescox fills in this template, it will replace these keys with actual numerical values provided by the user. One could just as easily add a key for the projectile energy, number of angular steps, or any other Frescox input parameter.

The Configuration class encapsulates a particular Frescox input configuration. Configuration.from_template reads in a file like the one above, allows the user to pass in a python dict mapping keys to values to fill in the template, and writes the output. For example:

from bfrescox import Configuration

template_file = "path/to/ni78.template"
parameters = {
    "V": 50.0,
    "r": 1.25,
    "a": 0.65,
    "W": 10.0,
    # ... etc ...
}

config = Configuration.from_template(template_file, "ni78.nml",  parameters)

See the examples for more details on using and generating templates with Bfrescox.