float getAngle(int atomIndexA, int atomIndexB, int atomIndexC) {
		if (vectorBA == null) {
			vectorBA = new Vector3f();
			vectorBC = new Vector3f();
		}
		Point3f pointA = atoms[atomIndexA];
		Point3f pointB = atoms[atomIndexB];
		Point3f pointC = atoms[atomIndexC];
		vectorBA.sub(pointA, pointB);
		vectorBC.sub(pointC, pointB);
		float angle = vectorBA.angle(vectorBC);
		float degrees = toDegrees(angle);
		return degrees;
	}