X-ray Diffraction Laboratory



Crystallographic Density Calculator

Enter Formula. You may use the (), however do not proceed the formula with a number e.g. 5H2O use (H2O)5 instead. Short hand Me, Et, Pr, Bu, Ph, Ts, Aq

Formula      Volume   Z :  

Hints. If the density is too low, try adding solvent molecules. If the density is an multiple of the expected number try changing Z. If all else fails consider a new formula

This table represents the most likely range of values for a particular chemical compound.  To use this table, first determine the heaviest element present in your compound.  Find the nearest match in the table and read the lower and upper limits (quartiles).  The density of your compound will most likely fall somewhere between these limits.

Element Type

Lower Quartile

Upper Quartile

Range g/cm3

% of total

+ C

1.065 g/cm3

1.295 g/cm3

1.1 – 1.3

0.7

+ N

1.097

1.364

1.1 – 1.4

1.4

+ O

1.176

1.479

1.1 – 1.5

8.2

+ S

1.226

1.553

1.2 – 1.6

7.2

1st row TR

1.275

1.873

1.3 – 1.9

3.9

+ Br

1.361

1.956

1.4 – 2.0

2.7

Data :  The data is represented as the lower and upper Quartiles of the distribution of the densities of compounds, where that element is both present and is the heaviest element allowed for that set.  The data is generated from the examination of 115,236 structures (each with R£0.05, no errors and no disorder)(Cambridge Crystallographic Data Base, October 2002; Allen, F.H. 2002). Structures with no reported densities (density=0) were not included in the final distributions.