In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The incidence of akathisia was low and similar with quetiapine monotherapy ( 3 . 3 % ) and placebo ( 6 . 1 % ) , and with QTP + Li / DVP ( 3 . 6 % ) and PBO + Li / DVP ( 4 . 9 % ) .
### Output Text:
The incidence of akathisia was low and similar with <span class="chemical">quetiapine</span> monotherapy ( 3 . 3 % ) and placebo ( 6 . 1 % ) , and with <span class="chemical">QTP</span> + <span class="chemical">Li</span> / <span class="chemical">DVP</span> ( 3 . 6 % ) and PBO + <span class="chemical">Li</span> / <span class="chemical">DVP</span> ( 4 . 9 % ) . 