Low Tm score

If a structure's Tm score is low, how can that score be made better? Like I have Tm of 0.40±0.13 for model1 (best predicted) for my query sequence, which is beyond the approximate range (0.5-1). My results are available at http://zhanglab.ccmb.med.umich.edu/I-TASSER/output/S210064/.

Can someone please help me in solving this problem? Thanks in advance!