13444
Photoelectron imaging experiments and detailed calculations are conducted on Al ( n ) ( - ) clusters ( n = 3 - 6 ) and a calibration method is developed for connecting experimental observations of photoelectron angular distributions to theoretical predictions .
 Chemical: Al ( n ) ( - )
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Al ( n ) ( - )