DAT

This type of file can be imported directly into a spreadsheet or other graphical display package. It is a simple (x,y,e) ASCII format with a file header:

ACETONITRILE Ref: J.CS. Farad.Trans. 87 (1991) 539. J.W.White, ANU, Canberra, Australia
C (CM-1) COUNTS ERROR
1.613200E+01 4.913682E-10 7.514824E-11
1.621266E+01 6.585508E-10 8.950449E-11
1.629372E+01 6.133741E-10 8.619769E-11
1.670516E+01 5.965735E-10 8.303958E-11
.
.
3.972105E+03 3.953404E-10 2.531102E-11
3.991966E+03 3.758412E-10 2.471038E-11

The first line is the name of the compound, its principal investigator (this is not necessarily the person who actually measured the spectrum), their affiliation and the literature reference (if known). The second line defines the units, for the energy transfer (i.e. x) axis all the spectra are given in units of wavenumbers, cm^-1, (1 meV=8.067 cm^-1). The counts (i.e. y) column is the scattered intensity and is directly proportional to the scattering function S(Q,w. The error column (i.e. z) is given by the square root of the number of counts, since Poisson statistics apply to the measurement process.
It is also suitable for use with the INS spectra analysis program CLIMAX. If this is the goal, then users should be aware that while the line positions will be given correctly, the phonon wings will be displaced by 16 cm^-1 to lower energy since CLIMAX assumes the first data point is at zero for the wings. To overcome this, three lines should be inserted before the first data point, bringing the x and y values smoothly to almost (~10^-3 cm^-1) zero.