/* $Revision$ $Author$ $Date$
*
* Copyright (C) 2005-2007 Christian Hoppe <chhoppe@users.sf.net>
* 2008 Egon Willighagen <egonw@users.sf.net>
*
* Contact: cdk-devel@list.sourceforge.net
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.openscience.cdk.charges;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.openscience.cdk.annotations.TestClass;
import org.openscience.cdk.annotations.TestMethod;
import org.openscience.cdk.exception.CDKException;
import org.openscience.cdk.interfaces.IAtomContainer;
import org.openscience.cdk.tools.HOSECodeGenerator;
/**
* Assigns charges to atom types.
*
* @author chhoppe
* @cdk.created 2004-11-03
* @cdk.module charges
* @cdk.githash
*/
@TestClass("org.openscience.cdk.charges.AtomTypeChargesTest")
public class AtomTypeCharges implements IChargeCalculator {
HOSECodeGenerator hcg = new HOSECodeGenerator();
Pattern pOC = Pattern.compile("O-[1][-];=?+C[(]=?+O.*+");
Pattern pOP = Pattern.compile("O-[1][-];=?+P.*+");
Pattern pOS = Pattern.compile("O-[1][-];=?+S.*+");
Pattern p_p = Pattern.compile("[A-Za-z]{1,2}+[-][0-6].?+[+].*+");
Pattern p_n = Pattern.compile("[A-Za-z]{1,2}+[-][0-6].?+[-].*+");
/**
* Constructor for the AtomTypeCharges object
*/
AtomTypeCharges() { }
/**
* Sets initial charges for atom types
* +1 for cationic atom types
* -1 for anionic atom types
* carboxylic oxygen -0.5
* phosphorylic oxygen -0.66
* sulfanilic oxygen -0.5
* or to formal charge (which must be determined elsewhere or set manually)
* polycations are not handled by this approach
*
*@param atomContainer AtomContainer
*@return AtomContainer with set charges
*@exception Exception Description of the Exception
*/
@TestMethod("testCharges_pOC,testCharges_pOP,testCharges_pOS,testCharges_p_p,testCharges_p_n")
public IAtomContainer setCharges(IAtomContainer atomContainer) throws Exception {
atomContainer = setInitialCharges(atomContainer);
return atomContainer;
}
private String removeAromaticityFlagsFromHoseCode(String hoseCode){
//clean hosecode
String hosecode="";
for (int i=0;i<hoseCode.length();i++){
if (hoseCode.charAt(i)== '*'){
}else{
hosecode=hosecode+hoseCode.charAt(i);
}
}
return hosecode;
}
/**
* Sets the initialCharges attribute of the AtomTypeCharges object
*
*@param ac AtomContainer
*@return AtomContainer with (new) partial charges
*@exception CDKException Description of the Exception
*/
private IAtomContainer setInitialCharges(IAtomContainer ac) throws CDKException {
Matcher matOC = null;
Matcher matOP = null;
Matcher matOS = null;
Matcher mat_p = null;
Matcher mat_n = null;
String hoseCode = "";
for (int i = 0; i < ac.getAtomCount(); i++) {
try {
hoseCode = hcg.getHOSECode(ac, ac.getAtom(i), 3);
} catch (CDKException ex1) {
throw new CDKException("Could not build HOSECode from atom " + i + " due to " + ex1.toString(), ex1);
}
hoseCode=removeAromaticityFlagsFromHoseCode(hoseCode);
matOC = pOC.matcher(hoseCode);
matOP = pOP.matcher(hoseCode);
matOS = pOS.matcher(hoseCode);
mat_p = p_p.matcher(hoseCode);
mat_n = p_n.matcher(hoseCode);
if (matOC.matches()) {
ac.getAtom(i).setCharge(-0.500);
} else if (matOP.matches()) {
ac.getAtom(i).setCharge(-0.666);
} else if (matOS.matches()) {
ac.getAtom(i).setCharge(-0.500);
} else if (mat_p.matches()) {
ac.getAtom(i).setCharge(+1.000);
} else if (mat_n.matches()) {
ac.getAtom(i).setCharge(-1.000);
} else {
ac.getAtom(i).setCharge(new Double(ac.getAtom(i).getFormalCharge()));
}
}
return ac;
}
@TestMethod("testCharges_pOC,testCharges_pOP,testCharges_pOS," +
"testCharges_p_p,testCharges_p_n")
public void calculateCharges(IAtomContainer container) throws CDKException {
try {
this.setInitialCharges(container);
} catch (Exception exception) {
throw new CDKException(
"Could not calculate Gasteiger-Marsili PEPE charges: " +
exception.getMessage(), exception
);
}
}
}