Nmredata object structure

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Possible structure of the object including NMReDATA reflecting the format of NMReDATA tags of SDF files.

Note: This is not designed to include ambiguities in the assignment. This is therefore only for use with Level=0.

Chemical structure

For the structure part originating from the .mol part of the SDF file:

object.structure (from the .mol part of the file)

object.structure.atom[n] (for each atom n) 
object.structure.atom[n].N integer atomic number of atom N) 
object.structure.atom[n].X float x coordinate in A 
object.structure.atom[n].Y float y coordinate in A 
object.structure.atom[n].Z float z coordinate in A 

object.structure.bond[m] (for each bond m)
object.structure.bond[m].a1 int first atom (1 to number of atoms)
object.structure.bond[m].a2 int second atom (1 to number of atoms)
object.structure.bond[m].type int 1:for single bond, 2: for double bond, 3: for triple bond

Sample data

Information about the sample

object.version string version (content of the NMREDATA_VERSION tag)
object.level int level (content of the NMREDATA_LEVEL tag)
object.SMILE String smile code

When H are explicit in the structure, the SMILE code must also include all the H atoms in the smile code. The reason to include the smiles in the NMReDATA is that it can be used to generate pure text MNR description of spectra (This is under elaboration but it is very important for stability of the format to include them in SDF files!)

object.concentration float concentration in mM
object.temp float temperature in K


For the <NMR_ASSIGNMENT> (previously named NMR_SIGNALS>) of the SDF file: The signals of all isotopes are listed together, they compile the information from the tag describing the spectra (see below)

object.assignment[n] (for each assignment n)
object.assignment[n].label string label given to the atom or set of atoms
object.assignment[n].cs float chemical shift (single value, no range accepted!)
object.assignment[n].atom[m] integer atom number(s) assigned to the signal (start numbering at 1)

J couplings

For the <NMR_J> of the SDF file: This includes all the coupling extracted from the spectra (see below)

object.J[n] (for each coupling n listed)
object.J[n].label1 string label of the first signal 
object.J[n].label2 string label of the second signal 
object.J[n].value float coupling constant between label1 and label2

optional because possibly involving difficulties:

object.J[n].nb[m] int number of bonds between the atoms corresponding to the labels. 

In most cases, m = 1, but when the two labels correspond to more than one spin (for example in AA'XX' systems is described using a single lable for A and A' and a single label for X and X') the number of bonds depends on whether we consider A-X and A-X', this is why we need two elements in the tabel.

1D spectra

See also 1D spectra attributes page.

object.spectrum1d[n] (for each 1D spectrum n)
object.spectrum1d[n].S Multiplicity (string)
object.spectrum1d[n].J Scalar coupling (string) This is a string because it contains the description of the coupling, assignment, etc.
object.spectrum1d[n].N number of nuclei (int)
object.spectrum1d[n].L Label of the signal (string)
object.spectrum1d[n].E Integral (float)
object.spectrum1d[n].I Intensity (float)
object.spectrum1d[n].T1 T1 relaxation time (float)
object.spectrum1d[n].T2 T2 relaxation time (float)
object.spectrum1d[n].Diff diffusion rate (float)

2D spectra

See also 2D spectra attributes page.

object.spectrum2d[n] (for each 2D spectrum n)
object.spectrum2d[n].L1 Label of the signal in F1(string) (if the signal is not assigned, the chemical shift is given as a string)
object.spectrum2d[n].L2 Label of the signal in F2(string) (if the signal is not assigned, the chemical shift is given as a string)
object.spectrum2d[n].I Intensity (float)
object.spectrum2d[n].E Signal volume (float)
object.spectrum2d[n].Ja Active scalar coupling (float) i.e. from a COSY spectrum
object.spectrum2d[n].J1[m] Passive scalar coupling(s) in F1 (float)i.e. from a high-resolution COSY spectrum
object.spectrum2d[n].J2[m] Passive scalar coupling(s) in F2 (float)i.e. from a high-resolution COSY spectrum
object.spectrum2d[n].JL1[m] Label of the assigned passive coupling in F1 (string)i.e. from a high-resolution COSY spectrum
object.spectrum2d[n].JL2[m] Label of the assigned passive coupling in F2 (string')i.e. from a high-resolution COSY spectrum