20.1 Obtaining the Atomic Symbol of an Atom/Element

To simplify the task of dealing with the elements of the periodic table, OEChem contains several functions to obtain useful properties of the elements.

A common task is to obtain or display the atomic symbol of an atom represented by an OEAtomBase. To save space and reduce redundancy and consistency issues the OEAtomBase class contains only an unsigned integer representing the atom's atomic number. This value may be obtained using the OEAtomBase method GetAtomicNum. This value can be converted into an atomic symbol using the OEChem function, OEGetAtomicSymbol.

#include "oechem.h"
#include <iostream>

using namespace OEChem;
using namespace std;

int main()
{
   const char *symb = OEGetAtomicSymbol(OEElemNo::C);
   cout << "The atomic symbol for carbon is " << symb << endl;
}

The example above uses the unsigned integer constant OEElemNo::C from the OEElemNo namespace. This namespace represents the atomic numbers of the 109 elements as their symbols as a convenience.

The OEGetAtomicSymbol function always returns a valid const char * pointer. For atomic number zero and elements greater than or equal to OEElemNo::MAXELEM (currently 110), OEGetAtomicSymbol returns a pointer to the NUL character, '\0', i.e. an empty string. For all other (valid) values, the returned string contains one or two characters. The first character is always uppercase, and the second character, if it exists is lower case.

				OEChem - C++ Theory Manual Version 1.3.1

				OEChem - C++ Theory Manual Version 1.3.1