±±¾©Ê¯ÓÍ»¯¹¤Ñ§Ôº2026ÄêÑо¿ÉúÕÐÉú½ÓÊÕµ÷¼Á¹«¸æ
²é¿´: 709  |  »Ø¸´: 1

leijinping7888

½û³æ (³õÈëÎÄ̳)

±¾ÌûÄÚÈݱ»ÆÁ±Î

» ²ÂÄãϲ»¶

» ±¾Ö÷ÌâÏà¹Ø¼ÛÖµÌùÍÆ¼ö£¬¶ÔÄúͬÑùÓаïÖú:

ÒÑÔÄ   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

lb1586551

Í­³æ (СÓÐÃûÆø)

¡ï ¡ï ¡ï
Сľ³æ(½ð±Ò+0.5):¸ø¸öºì°ü£¬Ð»Ð»»ØÌû½»Á÷
aylayl08(½ð±Ò+2):ллÌÖÂÛ 2010-05-17 18:26:53
There is no unique answer to this question. The major problem is the limitation of the active space to 12-15 orbitals enforced by the method. In most cases this is no problem and the choice of active orbitals is obvious (for example the pi-orbitals in a conjugated system). The answer depends strongly on the problem under consideration. If it is a GS energy surface one should be careful to include all orbitals the occupation number of which may vary considerable along the path(s) followed on the surface. In excited states studies one need to include enough orbitals to describe the excited states. This often means both valence and Rydberg type orbitals.
In difficult cases it might be advantageous by starting a study with a RASSCF calculation where RAS2 only includes the open shell orbitals (if any), RAS1 the orbitals that can possibly be interesting as active, and RAS3 the corresponding correlating orbitals (often one just chooses all valence orbitals). By allowing 2-4 electrons in RAS3 one can get quite a good description of the near degeneracies. The result can be used to choose an active space for a CASSCF/CASPT2 calculation. Note that this test calculation may have to be performed on several places on an energy surface. In CASSCF calculations one should preferably use the same active space over the whole surface.
2Â¥2010-05-17 11:25:11
ÒÑÔÄ   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû
Ïà¹Ø°æ¿éÌø×ª ÎÒÒª¶©ÔÄÂ¥Ö÷ ѧԱNQWC8z µÄÖ÷Ìâ¸üÐÂ
×î¾ßÈËÆøÈÈÌûÍÆ¼ö [²é¿´È«²¿] ×÷Õß »Ø/¿´ ×îºó·¢±í
[¿¼ÑÐ] 0817»¯Ñ§¹¤³ÌÓë¼¼ÊõÇóµ÷¼Á£¬Ò»Ö¾Ô¸Öк£Ñó319 +8 lv945 2026-04-04 8/400 2026-04-04 23:41 by lqwchd
[¿¼ÑÐ] 338Çóµ÷¼Á +7 êɹ¦? 2026-04-03 7/350 2026-04-04 20:37 by À¶ÔÆË¼Óê
[¿¼ÑÐ] µ÷¼Á +4 ÊÇ¿ÉÀÖ²»ÊÇ¿ÉÀÖ 2026-04-04 4/200 2026-04-04 19:41 by ÌÆãå¶ù
[¿¼ÑÐ] 283·ÖÇóµ÷¼Á +5 ÊÔÊÔ¿´ß 2026-04-04 5/250 2026-04-04 17:06 by dongzh2009
[¿¼ÑÐ] 293·ÖÇóµ÷¼Á£¬ÍâÓïΪ¶íÓï +6 ¼ÓÒ»Ò»¾Å 2026-03-31 6/300 2026-04-04 14:57 by ´ÏÃ÷µÄ´óËÉÊó
[¿¼ÑÐ] ±¾¿Æ211£¬×¨Òµ085404£¬293·ÖÇëÇóµ÷¼Á +5 Á«²Ë¾ÍÊÇź°É 2026-04-04 5/250 2026-04-04 14:08 by ÕâÊÇÒ»¸öÎÞÁĵÄê
[¿¼ÑÐ] ÍÁľ304Çóµ÷¼Á +4 ÍÃͻͻͻ£¬ 2026-03-31 4/200 2026-04-04 13:34 by 1753564080
[¿¼ÑÐ] Ò»Ö¾Ô¸Äϲý´óѧ324Çóµ÷¼Á +9 hanamiko 2026-03-30 9/450 2026-04-04 11:04 by Öí»á·É
[¿¼ÑÐ] 278Çóµ÷¼Á +6 Yy7400 2026-04-03 6/300 2026-04-04 09:53 by zhangdingwa
[¿¼ÑÐ] 286Çóµ÷¼Á +8 lim0922 2026-04-02 8/400 2026-04-03 20:19 by rzh123456
[¿¼ÑÐ] 273Çóµ÷¼Á +20 ÀîÜÆÐÂ1 2026-03-31 20/1000 2026-04-03 09:58 by linyelide
[¿¼ÑÐ] ¸´ÊÔµ÷¼Á +3 bvzz 2026-04-01 3/150 2026-04-03 09:47 by À¶ÔÆË¼Óê
[¿¼ÑÐ] 301Çóµ÷¼Á +4 ϸ°ûÏà¹Øµ°°× 2026-04-02 8/400 2026-04-02 16:30 by 271179835
[¿¼ÑÐ] 285Çóµ÷¼Á +14 AZMK 2026-04-02 14/700 2026-04-02 15:54 by ÉϾÅÌìÀ¿Ô£¨ºÃÔ
[¿¼²©] ²ÄÁϹ¤³Ìרҵ˶ʿÉ격 +3 ÷ëÕýÓî 2026-03-30 3/150 2026-04-02 15:04 by greychen00
[¿¼ÑÐ] ÉúÎïѧ327£¬Çóµ÷¼Á +5 ÊéÉϵÄ÷×Ó 2026-04-01 6/300 2026-04-02 06:47 by ilovexiaobin
[¿¼ÑÐ] ½­ËտƼ¼´óѧÕвÄÁÏÑо¿Éú +4 Su032713. 2026-04-01 5/250 2026-04-01 22:03 by cccchenso
[¿¼ÑÐ] ÉúÎïѧ296Çóµ÷¼Á +10 ÌÀÔ²°ü 2026-03-29 14/700 2026-04-01 10:44 by Çóµ÷¼Ázz
[¿¼ÑÐ] µ÷¼ÁÉêÇë +8 ÕÅÕÅÕÅÕÅzy 2026-03-31 9/450 2026-04-01 08:29 by zjbkx
[¿¼ÑÐ] 083000»·¾³¿ÆÑ§Ó빤³Ìµ÷¼Á£¬×Ü·Ö281 +4 ³È×Ó£¨Ê¤Ò⣩ 2026-03-30 4/200 2026-03-31 00:44 by Linzejun
ÐÅÏ¢Ìáʾ
ÇëÌî´¦ÀíÒâ¼û