<DIV>Hi Gaters,</DIV> <DIV> </DIV> <DIV>I am tying to define new materials AB3C:(10%). Firstly I defined A, B, and C as element then I defined new material as:</DIV> <DIV> </DIV> <DIV>ABC: d= 4.5 g/cm3 ; n=3 ; state=solid</DIV> <DIV>        +el: name=A;    n=1<BR>        +el: name=B;    n=4<BR>        +el: name=C;    f=0.1</DIV> <DIV> </DIV> <DIV>When I run it I received this error:</DIV> <DIV> </DIV> <DIV><FONT color=#0000bf>This material is being already defined via element byatoms.</FONT></DIV> <DIV><FONT color=#0000bf>You are mixing apples and oranges..</FONT></DIV> <DIV><FONT color=#0000bf></FONT> </DIV> <DIV><FONT color=#000000>Can you help please?</FONT></DIV> <DIV> </DIV> <DIV>Best wishes.</DIV> <DIV> </DIV> <DIV><BR> </DIV><p> Send instant messages to your online friends http://uk.messenger.yahoo.com